#4 PLC MCQ - Quick Learn

Programmable Logic controller

Multiple choice questions

Question 1: The type of memory which is fast and temporarily stores the data which are immediately required for use is called as______.

a. HDD
b. ROM
c. RAM
d. SSD

Answer: RAM

Question 2: What is the largest integer number that a PLC counter function can reach if it uses a 16 bit register?

a. 32,768
b. 65,535
c. 65,536
d. 65,537
e. 32,767

Answer: 65,535

Question 3: How is the speed of operation of conventional relay system as compared to digital controllers?

a. Very slow
b. Very fast
c. Same
d. Almost similar

Answer: Very slow

Question 4: The PLC is used in _______.

a. Machine tools
b. Automated assembly equipment
c. Moulding and extrusion machines
d. All of the above

Answer: All of the above

Question 5: PLC can be ___________ in plant to change the sequence of operation.

a. only programmed
b. only reprogrammed
c. programmed and reprogrammed
d. able to give a set point

Answer: programmed and reprogrammed

Question 6: __________ of PLCs can be done in very little time.

a. Programming
b. Installation
c. Commissioning
d. All of the above

Answer: All of the above

Question 7: How is the noise immunity of PLCs to electrical noises as compared to that of conventional relay controllers?

a. poor
b. excellent
c. as good as noise immunity of conventional relay controllers
d. unpredictable

Answer: Poor

Question 8: The most popular language for PLCs is:

a. Ladder diagram
b. C++
c. OOP+
d. VHDL

Answer: Ladder diagram

Question 9: An AND function implemented in ladder logic uses:

a. Normally-closed contacts in series
b. Normally-open contacts in series
c. A single normally-closed contact
d. Normally-open contacts in parallel
e. Normally-closed contacts in parallel

Answer: Normally-open contact in series

Question 10: The PLC Can be categorized according to the

a. Power rating of the I/O module
b. Cost of the I/O module
c. Current rating of the I/O module
d. Number of I/O point

Answer: Number of I/O point