Automatic Process Control MCQs - Electrical and Electronic Instrumentation

This Portion of Electrical and Electronic Instrumentation contains Automatic Process Control MCQs (Multiple Choice Questions and Answers) / Objective Type Questions and Answers.

This Section covers below lists of topics.

Programmable Logic Controllers
Advantages of PLCs
The Control Program
Function of each Part in PLC
Hardware of PLC
System Addressing
PLC Operation and Program Scan
Implementation of Control Programs in PLC
More in Ladder Logic

PRACTICE IT NOW TO SHARPEN YOUR CONCEPT AND KNOWLEDGE

1. PLCs are ___________ designed for use in the control of a wide variety of manufacturing machines and systems.

special-purpose industrial computers
personal computers
electromechanical systems
all of the above

2. The first company to build PLCs was

general motors
Allen Bradley
square D
Modicon

3. Which of the following statements is not correct?

The PLC rung output [-( )-] is a discrete output instruction or bit in memory
Each rung of the ladder logic represents a logical statement executed in software—inputs on the right and outputs on the left
Input and output instructions in ladder logic do not directly represent the switches and actuators.
PLC input instructions are logical symbols associated with voltage at the input module terminals.

4. 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