DSSSB JE Electrical Previous Year Question Papers| 5 November 2019 Paper

Question 01: In a circuit shown below the voltage across 100 ohm resistance is

A. 50 V
B. 100 V
C. 60 V
D. 120 V

Question 02: Current in Ampere in an inductor is given by 10 + 10 t where t is the time in seconds. If the self- induced emf in the coil is 20 mV, then its self-inductance is:

A. 10 mH
B. 1 mH
C. 2 mH
D. 20 mH

Question 03: Equivalent resistance of the circuit shown below between X and Y

A. 6 ohm
B. 9 ohm
C. 18 ohm
D. 12 ohm

Question 04: Equivalent resistance seen between the terminal a and b for the circuit shown below is:

A. 20 ohm
B. 4 ohm
C. 25 ohm
D. 5 ohm

Question 05: Reciprocal of reluctance is

A. Reluctivity
B. Permeance
C. Permeability
D. Susceptibility

Question 06: An average voltage of 40 V is induced in a 1000 turn coil due to a change in flux which occurs in 0.5 seconds. The total flux change in webers is

A. 0.02
B. 0.05
C. 0.01
D. 0.04

Question 07: Two filament lamps rated 200 W/200 V and 50 W/200 V are connected in series across a 200 V, 50 Hz, ac supply. Then, the total power supplied by the source is:

A. 160 W
B. 80 W
C. 20 W
D. 40 W

Question 08: A battery having an open circuit voltage of 2 V has a terminal voltage of 1 V when supplying a current of 5 A. Its internal resistance is

A. 0.60
B. 0.40
C. 0.2 0
D. 0.1 0

Question 09: An iron cored choke coil has an equivalent resistance of 4 0. It draws 10fi from a single phase ac source of voltage 200 V, 50 Hz. Then, power consumed by the coil and its power factor respectively are:

A. 200 W, 0.2 lag
B. 400 W, 0.2 lag

Question 10: Mutual inductance between two closely coupled coils is 2 H. Now, if the number of turns in one coil is reduced by 50 percent and those of the other coil is doubled then, new value of mutual inductance is:

A. 2 H
B. 8 H
C. 1 H
D. 4 H

Question 11: In the circuit below, the value of resistance R is

A. 20 ohm
B. 30 ohm
C. 10 ohm
D. 40 ohm

Question 12: A conductor 0.2 m long is carrying a current of 20 A at right angles to a magnetic field of 0.5 Tesla. What will be force on the conductor of the current is increased by 50 percent?

A. 1 N
B. 4 N
C. 6 N
D. 3 N

Question 13: When applied with a unidirectional voltage, an inductor behaves virtually like a

A. Depends on the magnitude of voltage applied
B. Short circuit
C. Depends on the polarity of voltage applied
D. open circuit

Question 14: A non-ideal current source of 25 mA is supplying a resistive load of 5 kO. If the actual current flowing through the load is 20 mA, then the internal resistance of the source is:

A. 1 K ohm
B. 10 K ohm
C. 5 K ohm
D. 20 K ohm

Question 15: Three resistances are connected in parallel. Total circuit current is 6 A. Individual conductance of each parallel circuit are G1 = 1 S, G2 = 3 S, and G3 = 2 S. Then, current through G3 is:

A. 4 A
B. 1 A
C. 6 A
D. 2 A

Question 16: In the circuit shown below, the current drawn by the 6 0 resistor is 2 A. then the value of resistance R is

A. 9 ohm
B. 18 ohm
C. 3 ohm
D. 6 ohm

Question 17:Find Va – Vb in the following part of a closed circuit where Va and Vb are the potentials at a and b.

A. 10 V
B. 15 V
C. 5 V
D. 20 V

Question 18: Certain number of resistors having equal resistances offers an equivalent resistance of 1 0 when connected in parallel and 100 0 if they are connected in series. Then, the number of resistors and the resistance of each are

A. 20, 10 ohm
B. 5, 20 ohm
C. 20, 5 ohm
D. 10, 10 ohm

Question 19: The RMS value of a half-wave rectified symmetrical square wave current of 2 A is

A. √2 A
B. 1 A
C. 1/ √2 A
D. √3 A

Question 20: In a given circuit, the voltage across 9 ohm resister is

A. 54 v
B. 50 v
C. 75 v
D. 45 v

Question 21: In a synchronous generator supplying power at rated voltage with zero power factor lagging, the effect of armature reaction ampere turns is:

A. Demagnetizing
B. Cross magnetizing
C. Magnetizing
D. Magnetizing and cross magnetizing

Question 22: Field system of an alternator is usually excited from:

A. Single phase ac voltage
B. Square wave voltage
C. Three phase ac voltage
D. DC voltage

Question 23: Scott connected transformers can convert

(a) three-phase to two-phase
(b) two-phase to three-phase
(c) two-phase to four-phase
(d) three-phase to four-phase.

From the above options correct answer is:

A. a and c
B. b and c
C. b and d
D. a and b

Question 24: Torque developed by a motor while running at 1000 rpm is 106 N-m and the shaft torque available is 100 N-m. thesn the iron and mechanical losses in watts are:

A. 300 π
B. 50 π
C. 200 π
D. 100 π

Question 25:In a low power factor wattmeter compensating coil is connected:

A. In series with the current coil
B. In series with the pressure coil
C. In parallel with the pressure coil
D. In parallel with the current coil

Answer: In series with the pressure coil

Question 26: Loss of charge method is used for the measurement of:

A. High inductance
B. Low resistance
C. Low inductance
D. High resistance

Question 27: During plugging of a three-phase induction motor:

A. Rotor circuit is opened
B. Phase sequence of the stator voltage is reversed
C. One phase of stator is short circuited
D. Dc source is connected to stator

Answer: Phase sequence of the stator voltage is reversed

Question 28: A transformer is supplying a unity power factor load. Power factor on primary side will be

B. unity
D. zero

Question 29: A dc shunt generator has a critical field resistance of 400 0 at 1200 rpm. Now if the speed of the generator is increased to 1800 rpm what is the change in the critical resistance?

A. Increases to 900 ohm
b. Remains the same
c. Increases to 600 ohm
d. Decreases to 267 ohm

Question 30: A three phase star connected alternator develops an rms voltage of V1 per phase at the fundamental frequency. It also generates a third harmonic component whose rms value is V3 . What is the line voltage of the alternator?

Question 31: In hydro-electric plants the type of alternator used is:

A. Turbo generator
B. Non salient pole
C. Salient pole
D. Steam turbine generator

Question 32: A current transformer has a phase error of +5 degree. The phase angle between the primary and secondary current is:

A. 5 degree
B. 95 degree
C. 175 degree
D. 85 degree

Question 33: Ferranti effect on long overhead lines is experienced when:

A. Power factor is unity

Question 34: A 400 V three phase 50 Hz balanced source is supplying power to a balanced three phase load. Line current flowing through the load is 5A at a power factor angle of 30 degrees lagging. Reading of two wattmeters used to measure the load power are:

A. 1000 W, 2000 W
B. 2000 W, 4000 W
C. 2000 W, 3000 W
D. 1000 W, 3000 W

Question 35: An industrial consumer has a load pattern of 2000 kW at 0.8 lagging for 12 hours and 1000 kW at unity power factor for 12 hours. Its load factor is

A. 0.6
B. 0.8
C. 0.5
D. 0.75

Question 36: Current flowing in a circuit is i = (18 + 10sinωt + 7sin2ωt). A moving iron ammeter is connected in the circuit to measure this current. The reading of the meter will be approximately:

A. 28 A
B. 35 A
C. 18 A
D. 20 A

Question 37: Moving-coil permanent magnet instruments can be used for the measurement of

A. AC and DC
B. AC only
C. DC only
D. half-wave rectified DC

Question 38:Form factor of sinusoidal AC signal is

A. 1.11
B. 0.11
C. 2.11
D. 3.11

Question 39: Voltage applied to a load is 100√2 sin500t. Current through the load is 10√2 sin(500t + π/3). The power consumed by the load is:

A. 500 W
B. 200 W
C. 1000 W
D. 2000 W

Question 40: A three-phase induction motor is running at 5 percent slip with certain load. If at this load the power input to the rotor is 2000 W, then the mechanical power developed by the motor is:

A. 2000 W
B. 2100 W
C. 1700 W
D. 1900 W

Question 41: In a particular circuit, a coil having a self- inductance of 2 H is required to carry a current of 4 A. A capacitor rated for 400 V is used across the coil in order to prevent sparking during breaking of the circuit. The value of capacitor needed is:

A. 120 µF
B. 100 µF
C. 400 µF
D. 200 µF

Question 42: unite of reluctance is:

A. Henry
B. Weber
C. Weber/m2
D. (Henry)-1

Question 43: In a transmission system if V is the transmission voltage, weight of copper needed is proportional to:

A. V

B. 1/V2

C. V2

D. 1/V

Question 44: Cost of power generation will be low if:

A. Load factor is low and diversity factor is high
B. Load factor is high and diversity factors is low
C. Load factor and diversity factor are low
D. Load factor and diversity factor are high

Question 45: Energy produced in a power station is 1440 MWh per day. What is the maximum demand of the station if its load factor is 0.5?

A. 120 MW
B. 280 MW
C. 60 MW
D. 140 MW

Question 46: Sag of the conductors of a transmission line is 2 m when the span is 200 m. Now if the height of the supporting tower is increased by 25 percent sag will

A. Increase by 25 percent
B. Reduce by 25 percent
C. Reduce by 12.5 percent
D. Remains unchanged

Question 47: A motor has to be selected for following load cycle. Load uniformly rising from zero to 100 hp in 10 minutes after which it is constant at 100 hp for the next 10 minutes, followed by no load period of 30 minutes. Suitable size of continuous rated motor is:

A. 100 hp
B. 25 hp
C. 50 hp
D. 200 hp

Question 48: In dielectric heating, the current flows through:

A. Air
B. Dielectric
C. Metallic conductor
D. The ionic discharge between dielectric medium and metallic conductor

Question 49: Gain of a buffer amplifier is:

A. Dependent on the circuit parameters
B. Unity
C. infinity
D. zero

Question 50: The most economical method of electrical braking is:

A. Plugging
B. Dynamic braking with self-excitation
C. Regenerative braking
D. Dynamic braking with separate excitation

ELECTRICAL ENGINEERING MCQ

This questions are very help full in your JE/AE exam electrical engineering MCQ

Question 01: Which material is used for the manufacture of brushes in DC motors?

B. Copper
C. Carbon
D. All of these

Question 02: Which among these devices are used to protect low voltage induction motor?

A. HRC fuse
B. Contactor starter
D. All of these

Question 03: Tap changing transformers are used for……….

A. stepping up the voltage
B. stepping down the voltage
C. both stepping up and stepping down the voltage
D. supplying low voltage current for instruments

Answer: both stepping up and stepping down the voltage

Question 04: An ammeter is a …………….. instrument.

A. Absolute instrument
B. Secondary instrument
C. Recording instrument
D. Integrating instrument

Question 05: For what voltage is Twin conductor bundle used in India?

A. 220 kV
B. 330 kV
C. 500 kV
D. 750 kV

Question 06: Which of the following machine will be preferred to charge the batteries?

A. Series motor
B. Shunt generator
C. Series generator
D. Series generator

Question 07: Which of the following motors is used in ceiling fan?

A. Universal motor
B. Induction motor
C. Series motor
D. Synchronous motor

Question 08: Electrostatic voltmeter instruments are suitable for ……………

A. AC work only
B. DC work only
C. Both AC and DC work
D. None of these

Answer: Both AC and DC work

Question 09: The failure % of electric motor is higher due to………….

A. Insulation failure
C. Bearing failure
D. None

Question 10: At what rated voltage is the shielded cable provided in a low voltage system?

A. Rated voltage < 1kv

B. Rated voltage > 1 kv
C. Rated voltage < 500 kv
D. None of them

Question 11: What is the given symbol represents in electrical system?

A. UPS
B. Rectifier
C. Inverter
D. Battery

Question 12: Which among these is the application of universal motors?

A. Fans
B. Washing machines
C. Hair dryers
D. Vacuum cleaners

Question 13: Which of the amongst is the first equipment placed in the uninterrupted power supply (UPS)?

A. Inverter
B. Battery
C. Rectifier
D. Any of these

Question 14: Which material has a lower dielectric strength at 50 Hz?

A. Bakelite
B. Glass
C. Air
D. Dielectric oil

Question 15: Which material is used for the manufacture of brushes in DC motors?

A. Graphite
C. Copper
D. All of these

Answer: Graphite (or carbon both correct)

Question 16: Which among these is a type test?

A. Bending test
B. Drainage test
C. Dielectric security test
D. All of these

Question 17: In a transformer,………is found by the short circuit test.

A. Copper loss
B. Hysteresis loss
C. Eddy current loss
D. Iron loss

Question 18: Non-loading heat run test on transformer is performed by means of

A. SC teat
B. OC test
C. Core balance test
D. Sumpner’s test

Question 19: In Transformer, oil is used for

A. Cooling the Transformer
B. Providing insulation to Transformer winding and for cooling the Transformer
C. Lubricating the Transformer
D. None

Answer: Providing insulation to Transformer winding and for cooling the Transformer

Question 20: Which material can be used upto a temperature of 130° C?

A. Mica
B. Cotton
C. Synthetic resin
D. All of these

[Free Download] SSC JE Previous Year Questions Jan 2018 SeconD Shift Set-1

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[ays_quiz id=”15″]

A. M1L2T-3I-1

B. M1L2T-3I-2

C. M-1L-2T3I2

D. M1L1T-3I1

Which one of the following statement is TRUE about the resistance of a conductor?

(A) The resistance of a conductor is inversely proportional to the length of the conductor.
(B) The resistance of a conductor is directly proportional to t he area of the conductor.
(C) The resistance of a conductor is inversely proportional to the pressure applied on the conductor.
(D) The resistance of a conductor is inversely proportional to the area of the conductor.

Answer (D) The resistance of a conductor is inversely proportional to the area of the conductor.

In parallel combination of resistances, the voltage is ___________ ?

(A) lower a cross largest resistance
(B) higher across larges t resistance
(C) same across each resistance
(D) higher across smaller resistance

Answer (C) same across each resistance

Electrical conductivity of a conductor is measured in __________.

(A) Siemens
(B) Ohms
(C) Siemens/meter
(D) Ohms/metre

(A) C/4
(B) 4C
(C) C/2
(D) 2C

(A) 10
(B) 100
(C) 20
(D) 0.1

(A) 0.2
(B) 2
(C) 20
(D) 200

(A) 0.33
(B) 0.65
(C) 0.24
(D) 0.47

(A) 40
(B) 30
(C) 20
(D) 60

What will be the color-coding of a resistor when the resistance of the resistor is 15 Ohms?

(A) Green-Brown-Black-Black
(B) Brown-Green-Brown-Brown
(C) Brown-Green-Black-Brown
(D) Brown-Green-Black-Black

Which one of the following statement is TRUE about the Kirchhoff’s voltage law?

(A) The algebraic sum of all the voltages around any closed path is infinite.
(B) The algebraic sum of all the voltages around any closed path is negative.
(C) The algebraic sum of all the voltages around any closed path is one.
(D) The algebraic sum of all the voltages around any closed path is zero.

Answer (D) The algebraic sum of all the voltages around any closed path is zero.

Which one of the following is the CORRECT statement for superposition theorem?

(A) The algebraic sum of all the voltages around any closed path is zero.
(B) The overall current in any part of a linear circuit is equal t o the algebraic sum of the currents produced by each source separately.
(C) The sum of currents entering a node is equal to the sum of currents leaving the node.
(D) The algebraic sum of all the voltages around any closed path is equal to one.

Answer The overall current in any part of a linear circuit is equal t o the algebraic sum of the currents produced by each source separately.

(A) ZL = Zs
(B) ZL = RL
(C) ZL = 2Zs
(D) XL = RL

(A) 8
(B) 7
(C) 4
(D) 3

(A) 8 – j4
(B) 8 +j4
(C) 4 +j8
(D) 4 -j8

(A) 40
(B) 20
(C) 10
(D) 5

(A) ML2T2A-2
(B) ML2T2A2
(C)ML2T-2A-2
(D)ML-2T-2A2

(A) Permeance
(B) Capacitance
(C) Inductance
(D) Reluctance

(A) 60
(B) 30
(C) 25
(D) 15

(A) 32
(B) 24
(C) 16
(D) 8

(A) 2
(B) 4
(C) 6
(D) 8

(A) 15
(B) 12
(C) 10
(D) 8

(A) 0.41
(B) 0.35
(C) 0.32
(D) 0.24

(A) 4.4
(B) 5.6
(C) 7.2
(D) 8.4

(A) 16.67
(B) 18.26
(C) 20.24
(D) 26

Which of the following is the unit of frequency of an AC signal?

(A) Hertz/Second
(B) Revolution
(C) Hertz
(D) Revolution/second

Which one of the following is the CORRECT relation between the peak value and RMS value of current for a sine wave?

(A) Ims = 0.06Ip
(B)Ims = 0.87Ip
(C) Ims = 1.414Ip
(D) Ims = 0.707Ip

(A) 76.44
(B) 86.34
(C) 110.34
(D) 188.38

(A) 0.08
(B) 0.8
(C) 1.4
(D) 2.6

(A) 9.4
(B) 8.6
(C) 8.2
(D) 7.2

(A) 0.025
(B) 0.034
(C) 0.046
(D) 0.064

What will be the transient time (in seconds) of a series RC circuit when the value of the capacitance is 600 microfarad and the value of the resistance is 20 kilo-Ohms?

(A) 10
(B) 12
(C)14
(D) 16

What will be the resonant frequency (in kHz) of a tank circuit when the capacitance and inductance of the circuit is 0.04 mF and 0.04 mH respectively?

(A) 5
(B) 6
(C) 4
(D) 1

(A) voltage
(B) current
(C) resistance
(D) phase angle

Which of the following statement is TRUE?

(A) A galvanometer can be converted into ammeter by connecting a low value of resistance in series with the galvanometer.
(B) A galvanometer can be converted into ammeter by connecting a low value of resistance in parallel with the galvanometer.
(C) A galvanometer can be converted into ammeter by connecting a high value of resistance in series with the galvanometer.
(D) A galvanometer can be converted into ammeter by connecting a high value of resistance in parallel with the galvanometer.

Answer (B) A galvanometer can be converted into ammeter by connecting a low value of resistance in parallel with the galvanometer.

Which of the statement is TRUE about megger?

(A) Megger is used for the measurement of voltage.
(B) Megger is used for the measurement of current.
(C) Megger is used for the measurement of insulation resistance.
(D) Megger is used for the measurement of breakdown voltage of insulation.

Answer (C) Megger is used for the measurement of insulation resistance.

Which of the following bridge is most suitable for the measurement of inductance of a coil?

(A) Owen’s Bridge
(B) Schering Bridge
(C) Wien’s Bridge
(D) Wheatstone Bridge

Determine the required value of series resistance (in Ohms) to convert a galvanometer into a voltmeter of reading 0.4 volt range when the resistance of the galvanometer is 40 ohms and the value of current for full-scale deflection is 4 mA.?

(A) 60
(B) 5.0
(C) 40
(D) 30

Questions asked in Nov 2019 I have created a mock test. This test paper will give you environment for you haw to solve paper.

Free mock test of UPPCL previous year exam questions asked in Nov-2019 second shift.

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[ays_quiz id=”13″]

The cut-off current in the fuse depends on:i) Current rating of the fuseii) Value of the prospective currentiii) Asymmetry of the fault current

a. (ii) and (iii)
b. (i) and (ii)
c. (i), (ii) and (iii)
d. (i) and (iii)

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. (i), (ii) and (iii)[/bg_collapse]

What does the above symbol indicate in an electrical wiring drawing?

a. Socket outlet 15 A
b. Fuse
c. Socket outlet 5A

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer c. Socket outlet 5A [/bg_collapse]

A hydro-electric generating station is supplied from a reservoir of capacity 5 x 106 cubic meter at a head of 200 meter. Find the total energy available in kWh, if the overall efficiency is 75%.

a. 2 x 106 kWh
b. 2 x 105 kWh
c. 2 x 107 kWh
d. 2 x 104 kWh

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer a. 2 x 106 kWh[/bg_collapse]

The electric switch to control any electrical equipment will act as a:

a. PD controller
b. Proportional controller
c. PID controller
d. ON/OFF controller

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. ON/OFF controller [/bg_collapse]

Identify the properties for neutral wire and earth wire from the given list.i) It is connected to the neutral point of the transformer that is earthed at the substation.ii) It is a solid earth at the substationsiii) Unbalanced current flows through itiv) Only fault current flows through it

a. Neutral wire: (i) and (iv); Earth wire: (ii) and (iii)
b. Neutral wire: (i), (iii) and (iv); Earth wire: (ii)
c. Neutral wire: (i) and (iii); Earth wire: (ii) and (iv)
d. Neutral wire: (i); Earth wire (ii), (iii) and (iv)

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. Neutral wire: (i) and (iii); Earth wire: (ii) and (iv) [/bg_collapse]

In a dc motor, the commutation is used to:

a. Convert dc current from armature conductor to ac current feedback to supply
b. Convert ac current from armature conductor to dc current feedback to supply
c. Convert dc current from supply to ac current in armature conductor
d. covert ac current from supply to dc current in armature conductor

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. Convert dc current from supply to ac current in armature conductor [/bg_collapse]

In an electric magnetic circuit, for establishing a magnetic field:

a. The movement of coil is required.
b. Energy need not be spent, though energy is required to maintain it.
c. Energy must be spent, though no energy is required to maintain it.
d. Energy is not at all required.

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. Energy must be spent, though no energy is required to maintain it. [/bg_collapse]

Which for the following transmission systems has the maximum efficiency?

a. Gear drive
b. Belt drive
c. Rope drive
d. Direct drive

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Ans. d. Direct drive
[/bg_collapse]

The Laplace transform of u(t) = 1, t > 0; u(t) = 0 for t < 0 is:

a. 1 / s
b. s
c. 1 /(s +1)
d. (s + 1)

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. 1 / s[/bg_collapse]

The height for the light points and junction boxes from the floor level should be:

a. 3.0 m to 4.0 m
b. 2.5 m to 3.0 m
c. 2.0 m to 3.5 m
d. 1.5 m to 2.5 m

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. 1.5 m to 2.5 m [/bg_collapse]

Which of the following methods is NOT used to develop damping torque in the measuring instruments?

a. Eddy current
b. Spring control
c. Fluid friction
d. Air friction

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. Spring control [/bg_collapse]

Which of the following switches is used to detect the level of liquid within a tank?

a. Float switch
b. Relay-based switch
c. Push-button switch
d. Electrical ON / OFF switch

[/bg_collapse]

Very low resistance, which is less than one ohm, could be measured using:

a. Earth tester
b. Megger
c. Kelvin’s bridge
d. Wheatstone bridge

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. Kelvin’s bridge [/bg_collapse]

The factors influencing costs and tariffs of electric supply are:

a. Standing charges that are independent of the output and (ii) running or operating charges that are proportional to the output.
b. Standing charges the are proportional to the output and (ii) running or operating charges that are independent of the output
c. Standing charges that are proportional to the output and (ii) running or operating charges that are proportional to the output
d. Standing charges that are independent of the output and (ii) running or operating charges that are independent of the output.

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer a. a. Standing charges that are independent of the output and (ii) running or operating charges that are proportional to the output.[/bg_collapse]

A long transmission line has a large capacitance. If such a line is open-circuited or connected to the very light load at the receiving end, the magnitude of the voltage at the receiving end becomes higher than the voltage at the sending end. Such a phenomenon is called:

a. Skin effect
b. Corona loss
c. Ferranti effect
d. Sag in transmission lines

[/bg_collapse]

The typical voltage value of the transformer that connects the generator output to the grid is:

a. 132 kV / 66 kV
b. 11 kV/ 132 kV
c. 66 kV / 132 kV
d. 33 kV / 3.3 kV

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. 11 kV / 132 kV
[/bg_collapse]

Which of the following functionalities is not possible in the PLC during the “Run Mode”?

a. Executes the ladder program and energises output devices.
b. Prevents online program editing.
c. Places the processor in the RUN mode.
d. Allows you to perform program entry and editing.

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]
Answer. d. Allows you to perform program entry and editing. [/bg_collapse]

With respect to liquids fuels, which statement of the following is incorrect?

a. The combustion of liquid fuels is uniform.
b. The handling of liquid fuels is easier and they require less storage space.
c. The firing of liquid fuels can be easily controlled.
d. Liquid fuels leave very large quantity of ash after burning as compared to solid fuels.

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. Liquid fuels leave very large quantity of ash after burning as compared to solid fuels [/bg_collapse]

a. Copper
b. Iron
c. Carbon
d. Brass

[/bg_collapse]

The SF6 circuit breakers are preferred for the substation with:

a. 33 kV
b. 11 kV
c. 110 kV
d. 220 kV

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. 220 kV [/bg_collapse]

The terminal voltage of a long shunt dc generator could be determined as:

a. V = Eg + la Ra
b. V = Eg – laRa
c. V = Eg + la(Ra + Rs)
d. V = Eg – la(Ra + Rs)

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer d. V = Eg – la(Ra + Rs)[/bg_collapse]

Active materials of a lead-acid cell are:

b. Lead peroxide and filler caps

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Ans. a. Lead peroxide, sponge lead and dilute sulfuric acid [/bg_collapse]

Which of the following statements is not true with respect to ac transmission systems?

a. The maintenance of ac sub-stations is easy and inexpensive.
b. The ac voltage can be stepped up or stepped down by transformers with ease and efficiency.
c. Due to skin effect in the ac system, the effective resistance of the line is decreased.
d. The power can be generated at high voltages.

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer c. Due to skin effect in the ac system, the effective resistance of the line is decreased.[/bg_collapse]

The law that describes the economic choice of conductor size is:

a. Fleming’s Law
b. Ohm’s law
d. Kelvin’s law

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. Kelvin’s law [/bg_collapse]

a. 56%
b. 29%
c. 45%
d. 66%

Line-to-ground fault occurs:

a. Due to short circuit between two conductors
b. Due to insulation breakdown between one of the phase and earth
c. Due to the breakdown of insulation between two phases and simultaneous breakdown of insulation between the third phase and earth
d. Due to fault breakdowns of insulation between two phases and earth occur

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. Due to insulation breakdown between one of the phase and earth [/bg_collapse]

The use of optical isolation in the input module side of a controller device is to:

a. Reduce the effect of electrical noise and prevent damage to the processor due to line voltage transient
b. Prevent damage the processor due to line voltage transient
c. Provide common ground
d. Reduce the effect of electrical noise

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. Reduce the effect of electrical noise and prevent damage to the processor due to line voltage transient [/bg_collapse]

In the overhead system the maximum disruptive stress exists between the:

a. Phase conductor and neutral
b. Conductor and the earth
c. Conductors
d. Conductor and pole

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. Conductor and the earth
[/bg_collapse]

The load side typical distribution system has:

a. 2 wire 440 V
b. 3 wire, 440 V
c. 4 wire, 440 V
d. 1 wire, 230 V

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. 4 wire, 440 V [/bg_collapse]

Which of the following Indian Electrical Rules describes the guarding in an electrical system?

a. Rule 88
b. Rule 84
c. Rule 85
d. Rule 75

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]

Consider the below points:i) Minimum size of cableii) Voltage dropiii) Current carrying capacityiv) Type of insulation used Which of the above constitute specifications that need be considered while selecting wires?

a. (I), (ii), (iii) and (iv)
b. (iv) and (ii)
c. (ii), (iii) and (iv)
d. (i), (ii) and (iii)

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. (I), (ii), (iii) and (iv) [/bg_collapse]

_________is an electromechanical device that consists of an actuator mechanically linked to a set of contacts. When an object comes into the contact with the actuator, the device operates the contacts to make or break an electrical connection.

a. A relay
b. A photoelectric switch
c. A circuit breaker
d. A limit switch

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. A limit switch [/bg_collapse]

With respect to automation, choose the wrong statement.

a. It provides better working conditions for workers
b. It decreases unemployment
c. The is an increase in productivity
d. There is a reduction in the production cost

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Ans. b. It decreases unemployment [/bg_collapse]

a. 92%
b. 30%
c. 27.6%
d. 62%

The objective of automation is to cause the work system to be automatic such that the system becomes:

a. Self-reliant only
b. Self-acting, self-regulating and self-reliant all
c. Self-regulating only
d. Self-acting only

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. Self-acting, self-regulating and self-reliant all [/bg_collapse]

In terms of energy bands, semiconductors can be defined as those materials that have:

a. Almost an empty conduction band and almost filled valence band with a very narrow energy gap between the conduction and valence band.
b. Almost an empty conduction band and almost filled valence band with a very high energy gap between the conduction and valence band
c. Almost and empty conduction band and low filled valence band with a very narrow energy gap between the conduction and valence band
d. Almost full conduction band and almost filled valence band with a very narrow energy gap between the conduction and valence band

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer a. Almost an empty conduction band and almost filled valence band with a very narrow energy gap between the conduction and valence band.[/bg_collapse]

In railway electrification, the voltage and frequency, respectively, of the three-phase AC system are:

a. 25 kV and 50 Hz
b. 3 to 3.5 kV and 16 2/3 Hz
c. 1500 V and 50 Hz
d. 600 V and 50 Hz

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer  b. 3 to 3.5 kV and 16 2/3 Hz[/bg_collapse]

Which of the following characteristics is not an electrical characteristic considered during the selection of a motor?

a. Running characteristics
b. Starting characteristics
c. Transmission of drive
d. Speed control

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. Transmission of drive[/bg_collapse]

Which of the following control methods in not preferred for AC drives?

a. Changing the supply frequency
b. Injecting resistance in the rotor circuit
c. Field control method
d. Changing the supply voltage

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]

The equipment that is used to disconnect the main under the no-load condition for safety isolation and maintenance is called:

a. Earthling switch
b. Isolator
c. Busbar
d. Line trap

Which option represents the correct sequence of the flow of the electrical power from the generating station to the load.

a. Primary transmission, secondary distribution
b. Primary transmission, primary distribution
c. Primary transmission, secondary transmission
d. Primary transmission, secondary transmission, primary distribution and secondary distribution

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. Primary transmission, secondary transmission, primary distribution and secondary distribution [/bg_collapse]

One lumen per square metre is termed as:

a. Candle power
b. MHCP
c. One lux
d. MSCP

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. One lux [/bg_collapse]

Which of the following control devices is used to provide protection against accidents by rapidly interrupting dangerous contact voltages that may be present in the electrical equipment’s as a result of ground faults, insufficient insulation, insulation failure, or misuse and sabotage?

a. Optical switch
b. Push-button control switch
c. Float switch
d. ELCB

Determine the pitch factor for winding: 36 stator slots, 4-poles, coil spans 1 to 8.

a. cos 20°
b. cos 40°
c. cos 30°
d. cos 80°

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. cos 20° [/bg_collapse]

In the case of alternator cooling, a large quantity of air is passed through sub slots, which are just below the main slots. Such type of cooling is known as:

a. Closed circuit ventilation
c. Multiple inlet system of ventilation
d. Axial ventilation

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. Axial ventilation [/bg_collapse]

A hydroelectric generating station is supplied from a reservoir of capacity 6 million m3 at a head of 170m. Determine the potential energy stored in this water.

a. 101° J
b. 109 J
c. 108 J
d. 1012 J

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. 1012 J [/bg_collapse]

With respect to damping system in instruments, choose the incorrect statement.

a. It should always oppose the activating torque
b. Damping system should produce damping torque only when position is in motion
c. Damping torque should be proportional to the velocity of pointer but independent of operating current
d. It must not affect the controlling torque

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. It should always oppose the activating torque [/bg_collapse]

Which of the following device system is capable of operating in high temperature with poor conditions in dusty, dirty, corrosive atmospheres and withstand shock and vibration?

a. Laptop
c. Personal computer
d. PLC

a. IS: 375-1985
b. IS: 675-1955
c. IS: 732-1989
d. IS: 375-1951

a. 010102
b. 100112
c. 100102
d. 010112

There exist three terminals in a relay called C, NO, NC, in an application, it is desired that whenever the relay is active the load must be connected be supply, otherwise the load will be disconnected from supply. Which of the following connection type in relay will provide solution to the stated problem?

a. Supply to the NC terminal and load to the C terminal
b. Supply to the C terminal and load to the NO terminal
c. Supply to the C terminal and load to the NC terminal
d. Supply to the NC terminal and load to the NO terminal

b. Supply to the C terminal and load to the NO terminal [/bg_collapse]

If the effective mass of the train = Me ton, acceleration = α Km/sec2, then the tractive force (Ft) is equal to:

a. Me x α x 106 N
b. Me x α x 103 N
c. Me x α x 105 N
d. Me x α x 104 N

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. Me x α x 106 N[/bg_collapse]

The required properties of traction batteries are:

a. High volumetric capacity and less service life
b. Low volumetric capacity and long service life
c. Constant output voltage, high resistance to vibration, and high volumetric and long service life
d. Constant output voltage, low resistance to vibration

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. Constant output voltage, high resistance to vibration, and high volumetric and long service life [/bg_collapse]

The cost of conductor material required can be reduced with the reduction in the volume of conduction material. This is possible with an:

a. increase in the frequency of the supply
b. increase in the transmission current
c. increase in the transmission voltage
d. increase in the transmission power

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. increase in the transmission voltage [/bg_collapse]

a. 5.2510

b . 5.12510

c. 5.62510

d. 6.62510

To improve earth resistance for protection which of the following methods is/are used?(i) Use longer ground rods(ii) chemically treat the soil(iii) use multiple ground rods

a. (i) and (ii)
b. (ii) and (iiI)
c. (ii) only
d. (i), (ii) and (iii)

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. (i), (ii) and (iii) [/bg_collapse]

Consider the below points:(i) Distance between stops(ii) Acceleration and retardation(iii) Gradient(iv)Train resistance Which of the above factors affect the specific energy consumption in trains?

a. (i) and (ii) only
b. (i), (ii), (iii) and (iv)
c. (ii) and (iii) only
d. (i), (ii) and (iii) only

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. (i), (ii), (iii) and (iv) [/bg_collapse]

a. Carbon
b. Thermistors
c. Varistors
d. Diodes

Which lightning stroke is most dangerous?

a. Direct stroke on the ground wire
b. Direct stroke on the line conductor
c. Indirect stroke on the conductor
d. Direct stroke on the tower top

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. Direct stroke on the line conductor [/bg_collapse]

Three capacitors of 2 μ F, 5 μ F and 10 μ F have breakdown voltage of 200 V, 500 V and 100 V respectively, The capacitors are connected in series and the applied direct voltage to the circuit is gradually increased. Determine the total applied voltage at the point of breakdown.

a. 320 V
b. 150 V
c. 250 V
d. 100 V

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. 320 V [/bg_collapse]

___________is a temperature sensitive resistor, whose resistance decreases with increasing temperature.

a. Proximity sensor
b. Copper wire sensor
c. Gold leaf sensor
d. Thermistor

Which of the following are the requirements for a good lighting system?(i) The illuminating source should have sufficient light(ii) The illuminating source should not strike the eyes(iii) The illuminating source should have suitable shades and reflectors.(iv) The illuminating source should be installed at such a place so as to give uniform light.

a. (ii), (iii) and (iv)
b. (i), (iii) and (iv)
c. (i), (ii), and (iv)
d. (i), (ii), (iii) and (iv)

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. (i), (ii), (iii) and (iv) [/bg_collapse]

A capacitor consists of two

a. Insulation separated by a dielectric
b. Conductors separated by an dielectric insulator
c. Ceramic plates and one mica disc
d. Silver coated insulators

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. Conductors separated by an dielectric insulator [/bg_collapse]

Which of the following sensors is used to measure the change in light quantity caused by the target crossing the optical axis?

a. A through- beam type sensor
b. LED
c. LASER
d. Reflective-type photoelectric sensor

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. A through- beam type sensor [/bg_collapse]

Which of the following is the advantage of a joint box system?

a. The fault location is easy to detect
b. The cost of wiring is saved
c. It require least skilled labour
d. No chance of short circuit

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. The cost of wiring is saved [/bg_collapse]

A steel- cored aluminium conductor consists of central core of wires surrounded by a number of:

a. galvanised steel; aluminium strands
b. copper; aluminium strands
c. aluminium; copper strands
d. aluminium; steel strands

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. galvanised steel; aluminium strands [/bg_collapse]

Which of the following magnetic materials is preferred for very-high-frequency communication systems?

a. Nickel-iron alloys containing up to 80% of nickel
b. Rolled steel
c. Forged steel
d. Nickel-iron alloys containing up to 20% of nickel

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. Nickel-iron alloys containing up to 80% of nickel [/bg_collapse]

Which of the following Indian Electrical Rules describes about the periodical and testing of consumer’s installation?

a. Rule 56
b. Rule 46
c. Rule 54
d. Rule 31

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. Rule 46 [/bg_collapse]

The CPU module in the PLC is used to:

a. control the outputs only
b. execute the control program only
d. read inputs, execute the control program and update output

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. read inputs, execute the control program and update output [/bg_collapse]

How to convert a (0 to 1) mA meter to measure the current in the range of 1 to 100 mA ? The internal resistance of the meter is 100Ω

a. Connect a 1.01 Ω resistance in series with the meter
b. Connect a 1.01 Ω resistance in parallel with the meter
c. Connect a 10.01 Ω. resistance in series with the meter
d. Connect a 10.01 Ω. resistance in parallel with the meter

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. Connect a 1.01 Ω, resistance in parallel with the meter [/bg_collapse]

Which of the following is not a peak power plant?

a. Gas plant
b. Solar and wind power plant
c. Diesel power plant
d. Thermal power plant

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. Thermal power plant [/bg_collapse]

The MVM instruction in PLC stands for:

a. Move data from memory to memory
b. Move data via direct memory access
c. Move data from reg to memory

In case of programmable automation, are there any changes/is there any change possible to be done in the sequence of operations?

a. Possible by changing the processor
b. Possible by changing the program
c. Possible by changing the embedded system
d. Not possible

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. Possible by changing the program [/bg_collapse]

To generate emf, which of the following methods may be used?(i) Stationary field system with rotating armature(ii) Stationary armature with rotating field system(iii) Stationary field and stationary armature

a. (i), (ii), and (iii)
b. (ii) only
c. (i) only
d. (i) and (ii)

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. (i) and (ii) [/bg_collapse]

It is decided that the copper rod earthing is to be installed, then the size of the rod required for earthing is:

a. 12.5 mm
b. 19 mm
c. 12.5 cm
d. 19 cm

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. 12.5 mm [/bg_collapse]

a. 2
b. 3
c. 1
d. 4

In a half adder, the carry output is high if the inputs are:

a. 1, 1
b. 0, 0
c. 0, 1
d. 1, 0

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. 1, 1 [/bg_collapse]

The cylindrical rotor type alternators are driven by:

a. Water turbine
b. Wind mill
c. Steam turbine
d. Solar cell

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. Steam turbine [/bg_collapse]

Which of the following has/have the highest stability and power rating?

a. Metal film resistors
b. Wire-wound resistors
c. Semiconductor film
d. Carbon composition resistors

A meter reads 125 V and the true value of the voltage is 125.5 V. Find the static error of the instrument.

a. 125/0.5 V
b. 125 V
c. 0.5 V
d. 0.5 / 125 V

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. 0.5 V [/bg_collapse]

If conductor is moved in a stationary magnetic field, then emf induced in it. Such an emf is known as:

a. Self-induced emf
b. Back emf
c. Static-induced emf
d. Dynamically-induced emf

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. Dynamically-induced emf [/bg_collapse]

The ratio a power plant’s actual output over a period of time to its potential output if it were possible for it to operate at full name plate capacity continuously over the same period of time is known as:

a. Demand factor
b. Diversity factor
d. Plant capacity factor

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. Plant capacity factor [/bg_collapse]

Which of the following devices has a typical analog output

a. Alarms
b. Horns
c. Pilot lights
d. Pressure transmitter

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. Pressure transmitter [/bg_collapse]

Which fault is more frequently occurring in power system?

a. Line to line fault
b. Double line to ground fault
c. Single line to ground fault
d. Symmetrical 3 phase fault

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. Single line to ground fault [/bg_collapse]

In a PMMC instrument, the final steady state deflection is:

a.α i, where i is the current through the coil
b. α 1 / i, where i is the current through the coil
c. α i2, where i is the current through the coil
d. α 1 / 12, where I is the current through the coil

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. α i, where i is the current through the coil [/bg_collapse]

The operating time values of fuse and circuit breakers are:

a. For fuse: around 0.02 second, and for circuit breaker: (0.002 to 0.005) second
b. For fuse: around 0.2 second, and for circuit breaker: (0.2 to 0.5) second
c. For fuse: around 0.002 second, and for circuit breaker (0.02 to 0.05)
d. For fuse: around 0.02 second, and for circuit breaker: (0.2 to 0.5) second

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. For fuse: around 0.002 second, and for circuit breaker: (0.02 to 0.05) [/bg_collapse]

Which of the following control devices is used to control/operate industrial equipment ?

a. PLC
b. Microprocessor
c. Discrete analog devices
d. DSP

The ____________is a temporary storage area used by the CPU to store a relatively _________ amount of data for interim calculations and control.

b. Application memory; large
c. Executive area; small

Which of the following law states that “whenever the magnetic flux lining a conductor or coil changes, an emf is induced in it?

a. Fleming’s right hand rule
b. Faraday’s first law of electromagnetic induction
c. Lenz’s law
d. Faraday’s second law of electromagnetic induction

The nature of emf induced in the armature of a dc generator ______ is and it is converted into ______ by means of split rings.

a. DC ; AC
b. AC ; AC
c. DC; DC
d. AC ; DC

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. AC ; DC [/bg_collapse]

In an alternator, when the armature current increases, the terminal voltage drops due to:

a. Armature reaction
b. Armature effective resistance, armature leakage reactance and armature reaction
c. Armature effective resistance
d. Armature leakage reactance

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. Armature effective resistance, armature leakage reactance and armature reaction [/bg_collapse]

For under water movement of a submarine the power is provided by:

a. tidal energy
b. MHD generator
c. batteries
d. Thermionic generator

Once a synchronous machine is synchronized, it will tend to remain in synchronism with the other alternators. Any tendency to depart from the condition of synchronism is produced due to circulating current flowing through the alternators.

a. Opposed by a motor torque
b. Opposed by a load torque
c. opposed by a synchronizing torque
d. Aided by a synchronizing torque

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. opposed by a synchronizing torque [/bg_collapse]

Let α be the angle, in electrical degrees, by which the span of the coil is less than a pole pitch in alternator. At the fundamental frequency, the pitch factor is equal to:

a. Cos α
b. Cos α/2
c. Sin α
d. Sin α/2

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. Cos α/2 [/bg_collapse]

With respect to dynamometer type measuring instruments, choose the incorrect statement.

a. They have a uniform scale
b. They can be used to measure both AC & DC
c. They are free from hysteresis and eddy current losses
d. They have Low torque/weight ratio

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. They have a uniform scale[/bg_collapse]

With respect to alternator rotor types, select the correct option.

a. Salient pole rotor type:- causes speed fluctuation and suitable for high-speed operation. Cylindrical rotor type:- causes no speed fluctuation and suitable for low-and medium-speed operation.
b. Salient pole rotor type:- causes speed fluctuation and suitable for- low and medium-speed operation. Cylindrical rotor type: causes no speed fluctuation and suitable for high-speed operation
c. Salient pole rotor type: causes no speed fluctuation and suitable for high-speed operation. Cylindrical rotor type: causes speed fluctuation and suitable for low-and medium-speed operation.
d. Salient pole rotor type: causes no speed fluctuation and suitable for low-and-medium speed operation. Cylindrical rotor type: causes speed fluctuation and suitable for high-speed operation.

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer b. Salient pole rotor type:- causes speed fluctuation and suitable for- low and medium-speed operation. Cylindrical rotor type: causes no speed fluctuation and suitable for high-speed operation[/bg_collapse]

The electrically-controlled magnetic materials used in machines should have:

a. low permeability and high saturation flux density
b. high permeability and high saturation flux density
c. Low permeability and low saturation flux density
d. high permeability and low saturation flux density

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. high permeability and high saturation flux density[/bg_collapse]

The loads in metal cutting and drilling tool drives, drives for forklift trucks, mine hoist etc. are considered to be:

a. Intermittent periodic duty in the starting
b. Short time duty
c. Continuous duty
d. Continuous duty with staring and braking

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. Intermittent periodic duty in the starting [/bg_collapse]

The direction of the magnetic field around the current-carrying conductor could be determined by:

a. Right hand thumb rule
b. Left hand thumb rule
c. Lenz’s law
d. Fleming’s right hand rule

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. Right hand thumb rule [/bg_collapse]

The capacitance of capacitor is NOT influenced by

a. Plate thickness
b. Plate area
c. Plate separation
d. Nature of the dielectric

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. a. Plate thickness [/bg_collapse]

Which of the following is not run with the help of DC supply?

a. Compound motor
b. Series motor
c. Shunt motor
d. Squirrel cage motor

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. Squirrel cage motor [/bg_collapse]

The maintenance cost for the electrical equipment is called.

a. Depreciation cost
b. Investment cost
c. Auxiliary cost
d. Operating cost

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. d. Operating cost [/bg_collapse]

In the measuring instruments, the degree of conformity and closeness to the true value is known as:

a. Precision
b. Deflecting torque
c. Measuring scale
d. Accuracy

The surge tanks are usually provided in high or medium head _________ power plants when considerably _______ is required.

a. Hydro-electric, short penstock
b. Hydro-electric, long penstock
c. Thermal, short penstock
d. Thermal, large steam turbine

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. Hydro-electric, long penstock[/bg_collapse]

a. High
b. Different
c. Low
d. Same

The generation of power in a power plant has to be controlled to meet the:

a. Demand of load and power factor
c. Demand of load and frequency
d. Frequency and power factor

In electrical wiring, the fuse should be placed:

a. In earth wire
b. In live or phase wire
c. In lamp directly
d. Neutral wire

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. In live or phase wire [/bg_collapse]

The overall efficiency of a steam power station is computed as:

a. (Steam energy) / (heat of combustion of coal)
b. (Heat equivalent of electrical output) / (Heat of combustion of coal)
c. (Heat equivalent of mechanical energy transmitted to turbine shaft) / (Heat of coal combustion)
d. (Heat of combustion of coal) / (Mechanical energy)

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. b. (Heat equivalent of electrical output) / (Heat of combustion of coal) [/bg_collapse]

ln terms of energy bands, insulators have:

a. Full conduction band
b. Very small energy gap
c. Full valence band
d. Moderate energy gap

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. Full valence band [/bg_collapse]

If a single motor drives a number of machines through belts from a common shaft, such a type of drive system is known as:

a. Individual drive
b. Complex motor drive
c. Multi motor drive
d. Group drive

Which of the following points represent the essential features of switchgear?i) Complete reliabilityii) Absolutely certain discriminationiii) Quick operationiv) Provision for manual control

a. (ii), (iii) and (iv) only
b. (i), (iii) and (iv) only
c. (i), (ii), (iii) and (iv)
d. (i), (ii) and (iii) only

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Answer. c. (i), (ii), (iii) and (iv) [/bg_collapse]

a. ELCB
b. Main switch
c. MCB
d. Energy meter

Before checking all questions and answer try below free mock test which. All questions are asked in 21-feb-2021 paper.

[ays_quiz id=”12″]

For subject wise if you want to give paper then click here

All Questions and Answer of MRPL 21-feb-2021

A cell of emf x and internal resistance y is connected to a resistance y. The potential difference between the terminals of the cell is

• x/2
• x/2y
• 2x/y
• x/(x+y)

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]

x/2

[/bg_collapse]

The ohm’s law deals with the relation between

• charge and resistance
• charge and capacity
• current and potential difference.
• capacity and potential difference.

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]

current and potential difference.

[/bg_collapse]

Potential inside a hollow charged sphere is

• same as on its sphere
• greater than on its surface
• less than on its surface
• zero

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]

same as on its sphere

[/bg_collapse]

Capacitance of a parallel plate capacitor decreases by

• increasing the area of plates
• increasing the distance between the plates
• putting a dielectric between the plates
• decreasing the distance between the plates

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]increasing the distance between the plates [/bg_collapse]

The capacitance of the two capacitors are in the ratio 1:2. When they are connected in parallel across supply voltage v, their charges will be in the ratio of

• 1:2
• 2:1
• 3:2
• 2:3

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]1:2[/bg_collapse]

The capacity of a cell depends upon

• Nature of plates material and electrolyte
• Sizes of the plates and the quality of electrolyte
• Both (A) and (B)
• None of the above

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Sizes of the plates and the quality of electrolyte[/bg_collapse]

When an organic compound is dissolved in water, the attractive forces between the charged atom reduce tremendously and they are separated this is called.

• Decomposition
• Deionisation
• Ionisation
• None of the above

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Ionisation [/bg_collapse]

Hysteresis loss in a magnetic material depends upon

• Area of hysteresis loop
• Frequency of reversed of field
• Volume of magnetic material
• All (A), (B) and (C)

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]All (A), (B) and (C)

[/bg_collapse]

Wheatstone bridge is used to measure

• Voltage
• Resistance
• Current
• Power

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Resistance [/bg_collapse]

The three resistors each of r ohm are connected in star. When they are transformed into delta connections, the resistance of each arm will be

• 2R ohm
• 3R ohm
• 4R ohm
• R/2 ohm

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]3R ohm

[/bg_collapse]

When a source is delivering maximum power to the load, the efficiency will be

• Maximum
• Before 50%
• Above 50%
• 50%

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]50%[/bg_collapse]

An alternating quantity which attains its positive maximum value prior to the other is called the

• In phase quantity
• Lagging quantity
• None of the above

If a sinusoidal wave has frequency of 50 Hz with 15 ampere rms value. Which of the following equation represents?

• 15sin5Ot
• 30sin25t
• 42.42sin 100t
• 21.21sin314t

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]21.21sin314t [/bg_collapse]

When a sinusoidal voltage is applied across a R-L series circuit having R XL, the phase angle will be

• 90°
• 30°
• 45°

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]45°

[/bg_collapse]

The shunt used in the millimetre

• Will extend the range and increases the resistance
• Will extend the range and decreases the meter resistance
• Will decrease the range and meter resistance
• Will decrease the range and increases the meter resistance

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Will extend the range and decreases the meter resistance [/bg_collapse]

A signal of 10mV at 75MHz is to be measured. Which of the following instruments can be used

• VTVM
• Cathode rayoscilloscope
• Moving iron voltmeter
• Digital multimeter

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]

Cathode rayoscilloscope

[/bg_collapse]

The pressure coil of a dynamometer type wattmeter is

• Highly inductive
• Highly resistive
• Purely resistive
• Purely inductive

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Highly resistive [/bg_collapse]

The dc series motors are preferred for traction applications because

• The torque is proportional armature current
• The torque is proportional to the square root of armature current
• The torque is proportional to square of armature Current and the speed is inversely proportional to the torque.
• Torque and speed are inversely proportional to armature current

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]The torque is proportional to square of armature Current and the speed is inversely proportional to the torque. [/bg_collapse]

What would happen if the field of d.c shunt motor is opened

• The speed of the motor will be reduced
• It will continue to run at its normal speed
• The speed of the motor becomes very high and may damage it.
• The current in the armature will decreases

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]The speed of the motor becomes very high and may damage it. [/bg_collapse]

The eddy current loss in the transformers occurs in the

• Primary winding
• Core
• Secondary winding
• None of the above

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Core[/bg_collapse]

1:5 step-up transformer has 120V across the primary and 600 ohms resistance across the secondary. Assuming 100% efficiency, the primary current will be:

• 0.2 Amp
• 5 Amp
• 10 Amp
• 20 Amp

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]10Amp[/bg_collapse]

The short circuit test in the transformers is performed to determine

• The iron loss at any load
• The hysteresis loss
• The eddy current loss

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]The copper loss at any load or any full load [/bg_collapse]

Regenerative method of braking is based on that

• Back emf is less than the applied voltage
• Back emf is equal to the applied voltage
• Back emf is more than the applied voltage
• None of the above

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Back emf is more than the applied voltage [/bg_collapse]

Which of the following can be used to control the speed of a d.c motor?

• Thermistor
• Thyristor
• Thyratron
• Transistor

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Thyristor

[/bg_collapse]

Which of the following motors is most suitable for signaling devices and many kinds of timers

• d.c shunt motor
• d.c series motor
• Inductance motor
• Reluctance motor

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Reluctance motor

[/bg_collapse]

Sparking at the commutators of a dc motor may result in

• Damage to the commutator’s segments
• Damage to the commutator’s insulation
• Increased power consumption
• All of the above

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]All of the above

[/bg_collapse]

According to Fleming’s right hand rule for finding the direction induced emf, when induced finger points in the direction of induced emf, forefinger will point the direction of

• Motion of conductor
• Lines offorce
• Either of the above
• None of the above

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Lines offorce [/bg_collapse]

The full load copper loss and iron loss of a transformer are 6400W and 5000W respectively the copper loss and iron loss at half load will be respectively.

• 3200W and 2500W
• 3200W and 5200W
• 1600W and 1250W
• 1600W and 5000W

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]1600W and 5000W
[/bg_collapse]

A 6 pole, 3 phase alternator running at 1000rpm supplies to an 8 pole, 3 phase induction motor which has a rotor current of frequency 2Hz. The speed at which the motor operates is.

• 1000 rpm
• 960 rpm
• 750 rpm
• 720 rpm

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]720 rpm[/bg_collapse]

The crawling in the induction motor Is caused by

• Improper design of stator lamination
• Low voltage supply
• Harmonics developed in motor

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Harmonics developed in motor [/bg_collapse]

The use of higher flux density in the transformer design

• Reduces the weight per kva
• Increases the weight per kva
• Has no relation with the weight of transformers
• Increases the weight per kw

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Reduces the weight per kva [/bg_collapse]

In hard-tool applications which one of the following single-phase motors is used

• Capacitor start motor
• Capacitor run motor
• AC series motor

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]AC series motor [/bg_collapse]

What is the angle between the induced voltage and supply voltage of a synchronous motor under running generation?

• Zero
• Greater than zero but =< 90°
• Between 90° and 180°
• 180°

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Greater than zero but =< 90° [/bg_collapse]

How can reactive power delivered by a synchronous generator be controlled?

• By changing the prime moves input
• By changing the excitation
• By changing the direction of rotation
• By hanging the prime moves speed

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]By changing the excitation[/bg_collapse]

When does a synchronous motor operate with leading power factor current?

• While it is under excited
• While it is critically excited
• While it is over excited
• While it is heavily loaded

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]While it is over excited

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In an induction motor what is the ratio of rotor copper-loss and rotor input

• 1/s
• s
• (1-s)
• s/(1-s)

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]s[/bg_collapse]

Select the correct answers using the code given below

• 2, 3 and 4
• 3 and 4
• 1, 2 and 3
• 1, 2 and 4

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]1, 2 and 4[/bg_collapse]

The pressure at the furnace is minimum in case of

• Force draught system
• Induced draught system
• Balanced draught system
• Natural draught System

[bg_collapse view=”button-orange” color=”#4a4949″ expand_text=”Show Answer” collapse_text=”Show Less” ]Balanced draught system

[/bg_collapse]

The commonly used material of condenser tube is

• Aluminium
• Cast iron
• Mild steel

[/bg_collapse]

Questions asked in Nov 2019 I have created a mock test. This test paper will give you environment for you haw to solve paper.

For subject wise if you want to give paper then click here

Free mock test of UPPCL previous year exam questions asked in Nov-2019 second shift.

[ays_quiz id=”11″]

Free mock test of PSPCL previous year exam questions asked in dec-2020. This is set 2 of Dec 2020 exam.

[ays_quiz id=”9″]

For subject wise if you want to give paper then click here

Top 50 Basic Electronics MCQ Part -2

This post contains Top 50 Basic Electronics MCQ. If you want to see my previous post on basic electronic part – 1 click here.

Please download basic electronics MCQ part 2 questions. For all MCQ topics like 8051 Microcontroller, 8086 Microprocessor, Power Electronics, PLC and SCADA you can check here

http://www.exam-labs.com/

Top 50 basic electronics multiple choice questions MCQ

Question 1 Choose the below option in terms of ascending order of band gap energy

• Diamond, Graphite, Silicon
• Graphite, Silicon, Diamond
• Silicon, Graphite, Diamond
• Silicon, Diamond, Graphite

Explanation

Diamond has the highest bandgap energy, about 6eV. It is this high bandgap which separates the filled valance band from the conduction band and makes Diamond an insulator.

Though Graphite is also a frm of Carbon, like Diamond, its crystal symmetry is different and band gap energy is about 1eV, making it a conductor.

Bandgap energy of Silicon is about 1.21eV, which can be acquired only with increase in temperature, making it a semiconductor

Question 2 Carrier lifetime for holes and electrons in a semiconductor ranges from

• Milliseconds to hundreds of nanoseconds
• Microseconds to seconds
• Nanoseconds to hundreds of microseconds
• Nanoseconds to thousands of milliseconds

Answer: Nanoseconds to hundreds of microseconds

Explanation

For an intrinsic semiconductor with equal concentration of holes and electron, the carrier lifetime for free electrons and holes is determined by the rate of recombination. While new electron-hole pairs are formed due to thermal agitation, existing electron-hole pair disappear due to recombination.

Question 3 Choose the below option in terms of ascending order of band gap energy

• Conduction and Diffusion
• Conduction
• Diffusion
• None of the above

Explanation

Two ways in which charge carriers are transferred in semiconductor are – conduction and diffusion

Conduction in semiconductor is accomplished by movement of free electrons and holes. While electrons are negative charge carrying particles, holes are positive charge carrying particles. Both their current is in same direction.

Diffusion is caused by movement of charge carriers from higher concentration area to lower concentration area. This is possible because of non-uniform concentration in semiconductors.

Question 4 The thickness of space charge region for a P-N junction diode is of the order of

• 10-4 cm
• 10-2 cm
• 10 cm
• 100 cm

Explanation

For a P-N junction diode, the space charge region is the region devoid of mobile charge carriers near to the junction. The electro-static potential variation in this region forms a potential barrier which opposes further diffusion of opposite charge carriers across the junction.

Question 5 Formation of a junction between a sample of P-type and N-type material causes _______ action

• Rectifying
• Conducting
• Insulating
• None of the above

Explanation

Addition of donor atoms into one side of an intrinsic semiconductor (like Germanium) and acceptor atoms into another side, causes formation of a junction. Under no external applied electric field, a potential barrier exists across the junction due to formation of depletion region (depletion of mobile charge carriers). However, when an external electric field is applied such that p-region is of positive polarity and n-region is of negative polarity, the potential barrier is reduced, causing flow of current. This is called Forward biasing.

When the opposite occurs, i.e. p-region is of negative polarity and n-region is of positive polarity, the potential barrier is increased, hindering the flow of current. Thus,  since the p-n junction device would allow flow of electricity in only one half of the electric signal, but not in the other half, this constitutes rectifying action.

Question 6 Cut-In or breakdown voltage of Silicon diode is greater than that of Germanium diode because ______.

• Reverse saturation current in a Silicon diode is lesser than that in Germanium diode
• Reverse saturation current in Germanium diode is lesser than that in Silicon diode
• The current is initially less dependent on voltage for a Silicon diode
• None of the above

Answer: Reverse saturation current in a Silicon diode is lesser than that in Germanium diode and The current is initially less dependent on voltage for a Silicon diode

Explanation

For a Germanium diode, the breakdown voltage is about 0.2 V, whereas that of Silicon diode is 0.6 Volts. The reason being that, reverse saturation current in a Ge diode is about 1000 times more than that in Si diode. Also, current flowing through the diode is as given below;

I = Io ( e V/ηVT  – 1 )

For Ge, the symbol  η = 1, whereas that for Si is 2 for small currents and 1 for large currents. Hence, for first several tenths of volts, the current varies as e V/2VT.

Question 7 The d.c. resistance of a crystal diode is ………….. its a.c. resistance

• The same as
• More than
• Less than
• None of the above

Explanation

• In the Crystal equivalent Circuit there is an Inductor [ L]& Capacitor [C] are series. The value of these L, C impedance varies with frequency and at resonance this cancels and only R – resistance is available which is equivalent to the DC Value.
• The impedance values of L & C changes in opposite directions at all other frequencies other than resonance and hence the AC Resistance is more .
• Therefore, the conclusion is DC resistance is less .

Question 8 A crystal diode is used as ……………

• an amplifier
• a rectifier
• an oscillator
• a voltage regulator

Explanation

The crystal diode can be used as a rectifier to convert the AC into DC. As it conducts only in one direction and blocks the current flow in the reverse direction as similar to the normal diode– it can be used to design the half wave, full wave and bridge rectifier circuits.

Question 9 Question 9 Band gap Energy for Silicon and Germanium at Room Temperature (300°K) are ____ & ____ respectively

• 56eV, 1.1eV
• 72eV, 1.2eV
• 1eV, 0.72eV
• 1eV, 0.56eV

Explanation

Below are the band gap energy relations with temperature for both Silicon and Germanium

Egsi (T) = 1.21 – 3.60 x 10-4

Egge (T) = 0.785 – 2.23 x 10-4

Substituting T = 300 in both the above equations, we get Bandgap energies as given below;

Egsi (300) = 1.1 eV

Egge (300) = 0.72 eV

Question 10 Depletion layer in semiconductor diode is caused by

• Doping
• Recombination
• Barrier potential
• Ions

Explanation

The depletion region is cause by the diffusion of charges. Because of the concentration gradient holes diffuse from p-side to the n-side across the junction while electrons diffuse from the n-side to the p-side. The holes and the electrons diffusing towards each other combine near the junction. In doing so positive and negative ions are formed. The pair of positive and negative ions at the junction forms the dipole. The region containing the dipoles and completely depleted of mobile charge is called the depletion region

Question 11 Zener diode can be described as

• A rectifier diode.
• A device with constant – voltage.
• A device with constant – current.
• A device that works in the forward region.

Answer: A device with constant – voltage.

Explanation

• A Zener diode is a heavily doped semiconductor device that is designed to operate in the reverse direction.
• Zener diodeis a silicon semiconductor devicethat permits current to flow in either a forward or reverse direction. … Additionally, the voltage drop across the diode remains constant over a wide range of voltages, a feature that makes Zener diodes suitable for use in voltage regulation

Question 12 Voltage multipliers produce

• Low voltage and low current
• Low voltage and high current
• High voltage and low current
• High voltage and high current

Answer: High voltage and low current

Explanation

voltage multiplier is a specialized rectifier circuit producing an output which is theoretically an integer times the AC peak input, for example, 2, 3, or 4 times the AC peak input. Thus, it is possible to get 200 VDC from a 100 Vpeak AC source using a doubler, 400 VDC from a quadrupler. Any load in a practical circuit will lower these voltages.

Question 13 A Diode is a

• Bilateral Device
• Nonlinear Device
• Linear Device
• Unipolar Device

Explanation

Diode is a Non Linear Device. Its just an electronic switch which turns on during forward bias and off during reverese bias. … A linear device is that whose output is directly propostional to input. In case of diode, output (i.e current) is not directly propostional to it input(i.e voltage across it).

Question 14 What is a Clamper?

• A circuit that adds a DC voltage (positive or negative) to a wave
• A circuit that adds a AC voltage (positive or negative) to a wave
• A circuit that removes a part (positive or negative) of a waveform
• All of the above

Answer: A circuit that adds a DC voltage (positive or negative) to a wave

Explanation

clamper is an electronic circuit that changes the DC level of a signal to the desired level without changing the shape of the applied signal.

In other words, the clamper circuit moves the whole signal up or down to set either the positive peak or negative peak of the signal at the desired level.

Question 15 What is a Clipper?

• circuit that adds a DC voltage (positive or negative) to a wave
• A circuit that adds a AC voltage (positive or negative) to a wave
• A circuit that removes a part (positive or negative) of a waveform
• All of the above

Answer: A circuit that removes a part (positive or negative) of a waveform

Explanation

clipper is a device which limits, remove or prevents some portion of the wave form (input signal voltage) above or below a certain level In other words the circuit which limits positive or negative amplitude ,or both is called chipping circuit.

Question 16 The reverse saturation current in a Silicon Diode is _____ than that of Germanium Diode

• Equal
• Higher
• Lower
• Depends on temperature

• In germanium diodes, a small increase in temperature generates large number of minority charge carriers.
• The number of minority charge carriers generated in the germanium diodesis greater thanthe silicon diodes. Hence, the reverse saturation current in the germanium diodes is greater than the silicon diodes.

Question 17 The forward voltage drop across a silicon diode is about ……

• 2.5 V
• 3 V
• 10 V
• 0.7 V

Question 18 A zener diode has ………..

• one pn junction
• two pn junctions
• three pn junctions
• none of the above

Question 19  A zener diode is used as …………….

• an amplifier
• a voltage regulator
• a rectifier
• a multivibrator

Question 20 A zener diode is always ………… connected.

• reverse
• forward
• either reverse or forward
• none of the above

Explanation

• A Zener diode is always reverse connected
• When forward biased, its characteristics are just like of ordinary diode
• It has sharp breakdown voltage, called Zener voltage

Question 21 A zener diode utilizes ……….. characteristics for its operation.

• forward
• reverse
• both forward and reverse
• none of the above

Question 22 A zener diode has ………….. breakdown voltage.

• undefined
• sharp
• zero
• none of the above

Explanation

• A Zener diode is always reverse connected
• When forward biased, its characteristics are just like of ordinary diode
• It has sharp breakdown voltage, called Zener voltage

Question 23 A zener diode is …………………. device

• a non-linear
• a linear
• an amplifying
• none of the above

Explanation

• A Zener diode is always reverse connected
• When forward biased, its characteristics are just like of ordinary diode
• It has sharp breakdown voltage, called Zener voltage

Question 24  ………. rectifier has the lowest forward resistance.

• solid state
• vacuum tube
• gas tube
• none of the above

Question 25 A series resistance is connected in the zener circuit to………...

• properly reverse bias the zener
• protect the zener
• properly forward bias the zener
• none of the above

Question 26 The disadvantage of a half-wave rectifier is that the…….

• components are expensive
• diodes must have a higher power rating
• output is difficult to filter
• none of the above

Answer: output is difficult to filter

Explanation

• They only allow a half-cycle through per sinewave, and the other half-cycle is wasted. This leads to power loss.
• They produces a low output voltage.
• The output current we obtain is not purely DC, and it still contains a lot of ripple (i.e. it has a high ripple factor)

Question 27 The Hall effect is used to determine the

• Only the carrier concentration of semiconductors
• Current flowing across a semiconductor
• Type of semiconductor and carrier concentration
• None of the above

Answer: Type of semiconductor and carrier concentration

Explanation

Hall effect is the phenomenon of induction of electric field in a semiconductor specimen carrying current of magnitude I, when placed in a transverse magnetic field, B. If current is in positive X direction, Magnetic field is in positive Z direction, force will be exerted in negative Y direction. The polarity of voltage, VH across the specimen determines whether it is N-type or P-type.

Also, carrier concentration is determined as:

n (p) = ρ/e, where ρ = charge density and e is magnitude of charge

Now, ρ = 1/RH,, where RH is Hall coefficient and is given as: RH = VHw/BI

w = width of the specimen in direction of magnetic field.

Question 28 The ripple factor of a half-wave rectifier is …………………

• 2
• 1.21
• 2.5
• 0.4

Question 29 For the same secondary voltage, the output voltage from a center-tap rectifier is ………… than that of bridge rectifier

• twice
• thrice
• four time
• one-half

Question 30 There is a need of transformer for ………………..

• half-wave rectifier
• Centre-tap full-wave rectifier
• bridge full-wave rectifier
• none of the above

Question 31 For the same secondary voltage, the output voltage from a centre-tap rectifier is ………… than that of bridge rectifier

• twice
• thrice
• four time
• one-half

Question 32 The PIV rating of each diode in a bridge rectifier is ……………… that of the equivalent centre-tap rectifier

• one-half
• the same as
• twice
• four times

Explanation

Peak inverse voltage(PIV) or peak reverse voltage(PRV) can be defined as the maximum value of the reverse voltage of a diode, which occurs at the peak of the input cycle when the diode is in reverse bias.

The PIV of bridge rectifiers is = Vm

The PIV of Center taped rectifiers is= 2Vm

The PIV (peak inverse voltage) ratings of the diodes in bridge rectifier is half than that of needed in a center tapped full wave rectifiers.

Question 33 A 10 V power supply would use …………………. as filter capacitor.

• paper capacitor
• mica capacitor
• electrolytic capacitor
• air capacitor

Question 34 A 1,000 V power supply would use ……….. as a filter capacitor

• paper capacitor
• air capacitor
• mica capacitor
• electrolytic capacitor

Question 35 The most widely used rectifier is ……………….

• half-wave rectifier
• centre-tap full-wave rectifier
• bridge full-wave rectifier
• none of the above

Explanation

• The efficiency of the bridge rectifier is higher than the efficiency of a half-wave rectifier. …
• The DC output signal of the bridge rectifier is smoother than the output DC signal of a half-wave rectifier.
• In a half-wave rectifier, only half of the input AC signal is used and the other half is blocked.

Question 36 The maximum efficiency of a half-wave rectifier is ………………..

• 40.6 %
• 81.2 %
• 50 %
• 25 %

Question 37 The ……………….. filter circuit results in the best voltage regulation

• choke input
• capacitor input
• resistance input
• none of the above

Question 38 A register with color bands: Yellow-Violet-Red, gold, has the value:

• 47k 5%
• 4k7 5%
• 470R 5%
• 47R 5%

Explanation

Digit, Digit, Multiplier = Colour, Colour x 10 colour  in Ohm’s (Ω)

For example, a resistor has the following coloured markings;

Yellow Violet Red = 4 7 2 = 4 7 x 102 = 4700Ω or 4k7 Ohm.

Question 39 The voltage out of an ideal voltage source is

• Zero
• Constant
• Internal resistance dependent

Explanation

An ideal voltage source has the following characterstic that allows it to act as a 100% efficient source of voltage: it has zero internal resistance. When an ideal voltage source has zero internal resistance, it can drop all of its voltage perfectly across a load in a circuit.

Question 40 The voltage out of an ideal current source is

• Zero
• Constant
• Internal resistance dependent

Explanation

An ideal current source generates a current that is independent of the voltage changes across it.

Question 41 The path between two points along which an electrical current can be carried is called

• A network
• A relay
• A circuit
• A loop

Question 42 If the Zener Diode is connected in wrong polarity, the voltage across the load is

• 0.7 V
• 10 V
• 14 V
• 18 V

Question 43 What is the tolerance of a resistor having sliver tolerance band

• 10%
• 5%
• 20%
• 2%

Question 44 PCB stands  for

• Proper circuit board
• Printed circuit board
• Printed circle board
• Printed circuit bond

Question 45 The chemical compound used for etching of PCB is

• Ferrous sulphate
• Ferric chloride
• Copper sulphate
• None of the above

Question 46 The specified deviation in the resistant value of a resister is called

• Capacitance
• Tolerance
• Inductance
• Color code

Explanation

This specified deviation is called ‘tolerance’. Every resistor has a specified tolerance range over which the resistance value is allowed to vary; anywhere from approximately 0.1% to 20% of the nominal value.

Question 47 Material classified as good conductors of electricity if

• The conduction and valence bands overlap
• There is a narrow forbidden, energy gap
• There is a wide forbidden, energy gap
• None of the above

Answer: The conduction and valence bands overlap

Question 48  ——- is an electronics component that opposes the flow of current

• Capacitor
• Resistor
• Inductor
• None of the above

Question 49 A resistors has the following color bands- yellow, violet, orange, silver. Its value will be

• 4.7 = 10%
• 47 + 5%
• 47k + 10%
• None of the above

Question 50 The number of holes in an intrinsic semiconductor is

• Equal to number of free electrons
• Greater than number of free electrons
• Less than number of free electrons
• None of the above

Answer: Equal to number of free electrons

I have explained all questions in this video. pdf of these question check at the end.

Hi All, In this series I explained top 20 objective questions and answer. For more questions of PLC and SCADA MCQ series. Please checkout my all MCQ series on PLC and SCADA. I have created MCQ series on Basic Electronics, Power Electronics, 8051 Microcontroller, 8086 Microprocessor.

If you are going to attempt any competitive exam then check your skills here. This is mock test questions which is asked in previous year paper in UPPCL, RSEB, Metro rail corporation and SSC JE.

[ays_quiz id=”2″]

Question 1 Which of the following statements about RLL is NOT true?

• NO contact symbol has two parallel lines to indicate an open contact.
• RLL stands for Relay Ladder Logic.
• NC contact symbol has the same two parallel lines with a line across them to indicate closed contacts.
• The right power rail is positive or the high side of the source, and the left power rail is the power return or ground.

Answer : The right power rail is positive or the high side of the source, and the left power rail is the power return or ground.

Question 2 _____ is a method of entering ladder logic representation.

• Segment programming
• TINT
• Boolean mnemonics
• All of the above

Question 3 When a relay is NOT energized

• There is an electrical path through the NO contacts
• There is an electrical path through the NC contacts
• Neither the NO or the NC contacts have an electrical path
• Both the NO and the NC contacts have an electrical path

Answer : There is an electrical path through the NC contacts

Question 4 In a current sinking DC input module _____

• The current flows out of the input field device
• Requires that a AC sources be used with mechanical switches
• The current flows out of the input module
• Currents can flow in either direction at the input module

Answer : The current flows out of the input field device.

Question 5 How is the speed of operation of conventional relay system as compared to digital controllers?

• Very slow
• Very fast
• Same
• Almost similar

Question 6 The type of memory which is fast and temporarily stores the data which are immediately required for use is called as______.

• HDD
• ROM
• RAM
• SSD

Question 7 _____ of PLCs can be done in very little time.

• Programming
• Installation
• Commissioning
• All of the above

Answer : All of the above

Question 8 How is the noise immunity of PLCs to electrical noises as compared to that of conventional relay controllers?

• Poor
• Excellent
• As good as noise immunity of conventional relay controllers
• Unpredictable

Question 9 _____ of PLCs can be done in very little time

• Programming
• Installation
• Maintenance
• All of the above

Answer : All of the above

Question 10 Which of the following statements is correct?

• Ladder logic is a PLC graphical programming technique introduced in the last 10 years.
• Ladder logic program is hard to analyze because it is totally different when compared with the equivalent relay logic solution.
• The number of ladder logic virtual relays and input and output instructions is limited only by memory size.
• The number of contacts for a mechanical relay is limited to number of coils on the relay.

Answer : The number of ladder logic virtual relays and input and output instructions is limited only by memory size.

Question 11 PLC can be _____ in plant to change the sequence of operation.

• Only programmed
• Only reprogrammed
• Programmed and reprogrammed
• Able to give a set point

Question 12 The PLC is used in _______.

• Machine tools
• Automated assembly equipment
• Molding and extrusion machines
• All of the above

Answer : All of the above.

Question 13 Which of the following can be the output of PLC?

1. Relay coils
2. Solenoids
3. Indicators
4. Motors
5. Lamps
6. Alarms

Select correct option

• Only (1), (2), (3) and (4)
• Only (3), (4), (5) and (6)
• Only (1), (2), (3) and (5)
• All the (1), (2), (3), (4), (5), and (6)

Answer : All the (1), (2), (3), (4), (5), and (6)

Question14 Instructions available in PLCs can be grouped in two categories: ________and ________ instructions.

Question15 What one item in the output module circuit above should be changed to make it correct.

• The battery polarity
• Output module should be sourcing
• Field device should be sinking
• Current flow direction

Question 16 Which of the following cannot be an input that is given to the PLC?

• Manual switches
• Relays
• Sensors
• None of the above

Answer : None of the above

Question 17 An AND function implemented in ladder logic uses

• Normally-closed contacts in series
• Normally-open contacts in series
• A single normally-closed contact
• Normally-open contacts in parallel

Answer : Normally-open contacts in series

Question 18 Ladder contacts can be programmed in

• series-parallel
• series or parallel
• a and b both true
• All of the above

Answer : a and b both true

Question 19 PLC instructions ___________.

• Uses the same symbols as relay logic.
• were copied using the original relay instructions
• Were added to the original relay instructions to make PLCs more powerful.

Answer : Were added to the original relay instructions to make PLCs more powerful.

Question 20 The L2 rail side of an electromechanical circuit is represented by _____________.

• The left side of the rail
• The right side of the ladder rung.
• sub-script lettering with arrows

Top 50 8051 Microcontroller MCQ – 2

Hi all, This is second part of 8051 microcontroller multiple choice questions series. In this MCQ series i have explained top 50 multiple choice questions. If you want to see more questions on 8051 microcontroller then check my previous post here.

This series will help in competitive exam like UPPCL- JE, SSC JE, RSEB, RRB and all competitive exam.

Please checkout all multiple choice questions like microcontroller, Power electronics, PLC and SCADA and 8086 microprocessor here. later I will add more questions in this series. So more update check frequently.

• 08H
• 09H
• 00H
• 07H

• MOVC & MOVY
• MOVY & MOVB
• MOVZ & MOVA
• MOVX & MOVC

• 00H to 7FH
• 01H to 7FH
• 00H to FFH
• 80H to FFH

Question 4 ……….. signal control the flow of data

• DTR
• RTS
• Both 1 & 2
• None of the above

Question 5 Register that is used to holds the memory address of the next instruction to be executed is

• Program Memory
• Program Counter
• Control Unit
• Instruction decoder

• Data Bus
• ALU
• Control Bus

Question 7 Why microcontrollers are not called general purpose computers?

• Because they have built in RAM and ROM
• Because they design to perform dedicated task
• Because they are cheap
• Because they consume low power

Question 8 What is the most appropriate criterion for choosing the right microcontroller of our choice?

• Speed
• Availability
• Ease with the product
• All of the mentioned

Question 9 A microcontroller at-least should consist of

• RAM, ROM, I/O ports and timers
• CPU, RAM, I/O ports and timers
• CPU, RAM, ROM, I/O ports and timers
• CPU, ROM, I/O ports and timer

• 128 bytes
• 256 bytes
• 64 bytes
• 512 bytes

Question 11 If we push data onto the stack then the stack pointer

• Increases with every push
• Decreases with every push
• Increases & decreases with every push
• None of the mentioned

MOV A,#9C

• CY=0,AC=0,P=0
• CY=1,AC=1,P=0
• CY=0,AC=1,P=0
• CY=1,AC=1,P=1

• DPTR
• B
• A
• PSW

Question 14 Unlike microprocessors, microcontrollers make use of batteries because they have

• high power dissipation
• low power consumption
• low voltage consumption
• low current consumption

Question 15 Are PUSH and POP instructions are a type of CALL instructions?

• yes
• no
• none of the mentioned
• cant be determined

Question 16 What is the time taken by one machine cycle if crystal frequency is 20MHz?

• 1.085 micro seconds
• 0.60 micro seconds
• 0.75 micro seconds
• 1 micro seconds

Question 17 What is the meaning of the instruction MOV A,05H?

• Data 05H is stored in the accumulator
• Fifth bit of accumulator is set to one
• Address 05H is stored in the accumulator
• None of the mentioned

Question 18 The upper 128 bytes of an internal data memory from 80H through FFH usually represent _______

• General-purpose registers
• Special function registers
• Stack pointers
• Program counters

Question 19 Which of the ports act as the 16 bit address lines for transferring data through it?

• PORT 0 and PORT 1
• PORT 1 and PORT 2
• PORT 0 and PORT 2
• PORT 1 and PORT 3

Question 20 Which operations are performed by the bit manipulating instructions of Boolean processor?

• Complement bit
• Set bit
• Clear bit
• All of the above

• Stack Pointer
• Program Counter
• Data Pointer
• All of the above

• TMOD
• TCON
• SCON
• PCON

Question 23 Why is it not necessary to specify the baud rate to be equal to the number of bits per second?

• Because each bit is preceded by a start bit & followed by one stop bit
• Because each byte is preceded by a start byte & followed by one stop byte
• Because each byte is preceded by a start bit & followed by one stop bit
• Because each bit is preceded by a start byte &followed by one stop byte

Question 24 Which is not the feature of 16-bit microcontroller?

• Large program & data memory spaces
• High speed
• I/O Flexibility
• Limited Control Applications

• PIN 28
• PIN 29
• PIN 30
• PIN 31

Question 26 How does the microcontroller communicate with the external peripherals / memory?

• Via I/O ports
• Via register array
• Via memory
• All of the above

Question 27 What is the order decided by a processor or the CPU of a controller to execute an instruction?

• decode, fetch, execute
• execute, fetch, decode
• fetch, execute, decode
• fetch, decode, execute

Question 28 How are the performance and the computer capability affected by increasing its internal bus width?

• It increases and turns better
• It decreases
• Remains the same
• Internal bus width doesn’t affect the performance in any way

• 8 bytes
• 32 bytes
• 16 bytes
• 128 bytes

Question 30 MOV A, @ R1 will:

• Copy R1 to the accumulator
• Copy the accumulator to R1
• Copy the contents of memory whose address is in R1 to the accumulator
• Copy the accumulator to the contents of memory whose address is in R1

• .doc
• .c
• .txt
• .hex

Question 32 Which control signal/s is/are generated by timing and control unit of 8051 microcontroller in order to access the off-chip devices apart from the internal timings?

• ALE
• PSEN
• RD & WR
• All of the above

• 32 bytes
• 64 bytes
• 128 bytes
• 256 bytes

• 1
• 2
• 5
• 8

• \$
• #
• @
• &

Question 36 Which of the following comes under the indexed addressing mode?

• MOVX A, @DPTR
• MOVC @A+DPTR,A
• MOV A,R0
• MOV @R0,A

Question 37 When we add two numbers the destination address must always be.

• Some immediate data
• Any register
• Accumulator
• Memory

Question 38 In 8 bit signed number operations, OV flag is set to 1 if:

• a carry is generated from D7 bit
• a carry is generated from D3 bit
• a carry is generated from D7 or D3 bit
• a carry is generated from D7 or D6 bit

Mode 0
Mode 1
Mode 2
Mode 3

Question 40 What is the frequency of the clock that is being used as the clock source for the timer?

• Some externally applied frequency f’
• Controller’s crystal frequency f
• Controller’s crystal frequency /12
• Externally applied frequency/12

Question 41 Which of the following signal control the flow of data?

• RTS
• DTR
• RTS & DTR
• None of the mentioned

Question 42 Which of the following best describes the use of framing in asynchronous means of communication?

• It binds the data properly
• It tells us about the start and stops of the data to be transmitted or received
• It is used for error checking
• It is used for flow control

Question 43 What is the difference between UART and USART communication?

• They are the names of the same particular thing, just the difference of A and S is there in it
• One uses asynchronous means of communication and the other uses synchronous means of communication
• One uses asynchronous means of communication and the other uses asynchronous and synchronous means of communication
• One uses angular means of the communication and the other uses linear means of communication

Question 44 Which devices are specifically being used for converting serial to parallel and from parallel to serial respectively?

• Timers
• Counters
• Registers
• Serial communication

• pin no 10
• pin no 11
• pin no 12
• pin no 13

• IE.D5
• IE.D2
• IE.D3
• IE.D4

Question 47 When an interrupt is enabled, then where does the pointer moves immediately after this interrupt has occurred?

• to the next instruction which is to be executed
• to the first instruction of ISR
• to a fixed location in memory called interrupt vector table
• to the end of the program

Question 48 After RETI instruction is executed then the pointer will move to which location in the program?

• next interrupt of the interrupt vector table
• immediate next instruction where interrupt is occurred
• next instruction after the RETI in the memory
• none of the mentioned

• pin no 1
• pin no 2
• pin no 3
• pin no 4

Question 50 For writing commands on an LCD, RS bit is

set
reset
set & reset
none of the mentioned

FAQ

What is Microcontroller?

Microcontroller is a combination of two words micro and controller, Micro means small in size and controller means a device that can control the operation of any system. So we can say that a microcontroller is a microprocessor with integrated peripherals.

What is the order decided by a processor or the CPU of a controller to execute an instruction?

First instruction is fetched from Program Memory, then fetching, instruction is decoded to generate control signals to perform the intended task. After decoding, instruction is executed and the complete intended task of that particular instruction.

How are the performance and the computer capability affected by increasing its internal bus width?

As the bus width increases, the number of bits carried by bus at a time increases as a result of which the total performance and computer capability increases.

How many bytes of bit addressable memory is present in 8051 based microcontrollers?

8051 microcontrollers have 16 bytes of bit addressable memory.

How many timers/counter 8051 microcontroller have?

8051 Microcontroller 8051 have 2 timers/counter.

When was intel design first 8051 microcontroller?

8051 microcontroller is designed by Intel in 1981. It is an 8-bit microcontroller

Why is CHMOS technology preferred over HMOS technology for designing the devices of MCS-51 family?

Micro Controllers are made by using the concept of VLSI technology. So here, CMOS based logic gates are coupled together by this technique that consumes low power.

8051 series has how many 16 bit registers?

8051 microcontroller has two 16 bit registers DPTR and PC.

8051 microcontrollers are manufactured by which of the following companies?

8051 microcontrollers are manufactured by Intel, Atmel, Philips/Signetics, Infineon, Dallas Semi/Maxim.

Which IO Port can be used for higher address byte with addresses A8-A15?

PORT2 : This port can be used for higher address byte with addresses A8-A15. When no memory is added then this port can be used as a general input/output port similar to Port 1.