1. . The acronym PLC stands for:
(A) Pressure Load Control
(B) Programmable Logic Controller
(C) Pneumatic Logic Capstan
(D) PID Loop Controller
2. . Ladder logic programming consists primarily of:
(A) Virtual relay contacts and coils
(B) Logic gate symbols with connecting lines
(C) Function blocks with connecting lines
(D) Text-based code
3. . Very often relays and valves are connected to:
(A) Input modules
(B) Output modules
(C) Any of these
(D) None of these
4. . PLCs that have a fixed amount of I/O capability built into the unit are known as:
(A) Rack PLCs
(B) Monolithic PLCs
(C) Modular PLCs
(D) None of these
5. . The universal gate is ………………
(A) NAND gate
(B) OR gate
(C) AND gate
(D) None of the above
6. . The inverter is ……………
(A) NOT gate
(B) OR gate
(C) AND gate
(D) None of the above
7. . The inputs of a NAND gate are connected together. The resulting circuit is …………
(A) OR gate
(B) AND gate
(C) NOT gate
(D) None of the above
8. . The NOR gate is OR gate followed by ………………
(A) AND gate
(B) NAND gate
(C) NOT gate
(D) None of the above
9. . The NAND gate is AND gate followed by …………………
(A) NOT gate
(B) OR gate
(C) AND gate
(D) None of the above
10. . Digital circuit can be made by the repeated use of ………………
(A) OR gates
(B) NOT gates
(C) NAND gates
(D) None of the above
11. . The only function of NOT gate is to ……………..
(A) Stop signal
(B) Invert input signal
(C) Act as universal gate
(D) None of the above
12. . When an input signal 1 is applied to a NOT gate, the output is ………………
(A) 0
(B) 1
(C) Either 0 & 1
(D) None of the above
13. . In Boolean algebra, the bar sign (-) indicates ………………..
(A) OR operation
(B) AND operation
(C) NOT operation
(D) None of the above
14. . An OR gate has 4 inputs. One input is high and the other three are low. The output is ……
(A) Low
(B) High
(C) Alternately high and low
(D) May be high or low depending on relative magnitude of inputs
15. . Both OR and AND gates can have only two inputs.
(A) True
(B) False
16. . The output will be a LOW for any case when one or more inputs are zero in a/an …………
(A) OR Gate
(B) NOT Gate
(C) AND Gate
(D) NAND Gate
17. . The logic gate that will have HIGH or “1” at its output when any one of its inputs is HIGH is a/an …………… gate.
(A) OR Gate
(B) NOT Gate
(C) AND Gate
(D) NAND Gate
18. . Which of the following method is used to minimize Boolean expressions?
(A) Fourier transform
(B) Gray code
(C) Karnaugh mapping
(D) Venitch method
19. . Four adjacent ‘1’s in a Karnaugh map forms a
(A) Octet
(B) Singlet
(C) Pair
(D) Quad
20. . A 4-variable Karnaugh map has
(A) 12 cells
(B) 16 cells
(C) 18 cells
(D) 20 cells
21. . In the Karnaugh map, each cell represents ___________ minterm derived from the Boolean expression.
(A) 1
(B) 2
(C) 3
(D) 4
22. . The sum or product of two minterms results in
(A) Maxterms
(B) Boolean expression
(C) Implicant
(D) None of the above
23. . Product-of-Sums expressions can be implemented using
(A) 2-level OR-AND logic circuits
(B) 2-level NOR logic circuits
(C) Both
(D) None
24. . The most popular language for PLCs is:
(A) Ladder diagram
(B) C++
(C) OOP+
(D) VHDL