Top 10 Multiple choice questions on Programmable logic controller
Question 1: The PLC was invented by.
- Bill Gates
- Dick Morley
- Bill Landis
- Tod Cunningham
Answer: Dick Morley
Question 2: The first company to build PLCs was.
- General Motors
- Allen Bradley
- Square D
- Modicon
Answer: Modicon
Question 3: Which part of plc monitors the inputs and makes decisions in a PLC.
- Sensor
- CPU
- Input Module
- Output Module
Answer: CPU
Question 4: One of the following is an input device.
- Motor
- Light
- Valve
- Sensor
Answer: Sensor
Question 5: Which one of the following is not a PLC manufacturer.
- Siemens
- Mitsubishi
- Microsoft
- ABB
Answer: Microsoft
Question 6: Solenoids, lamps, motors are connected to:
- Analog output
- Digital output
- Analog input
- Digital input
Answer: Digital output
Question 7: In a PLC “I” is used for output and “Q” is used for input.
- True
- False
- None of the above
Answer: False
Question 8: To increase the number of inputs and outputs of the PLC, one can use expansion modules.
- True
- False
- None of the above
Answer: True
Question 9: An example of discrete (digital) control is:
- Varying the volume of a music system
- Turning a lamp ON or OFF
- Varying the brightness of a lamp
- Controlling the speed of a fan
Answer: Turning a lamp ON or OFF
Question 10: Which of the following statements is NOT correct?
- The status of each input can be checked from one location and outputs can be forced on and off.
- All symbols in the RLL represent actual components and contacts present in the control system.
- PLCs are not as reliable as electromechanical relays in RLL.
- Input (-| |-) and output (- ( ) -) instruction symbols in the ladder logic represent only data values stored in PLC memory.