JEE Main - Basic logic gates and simple electronic circuits Online Test (MCQ Quiz)

1. Which logic gate produces an output of 1 only if all its inputs are 1?

A) OR gate B) AND gate C) NOT gate D) NAND gate

2. A NOT gate has an input of 0. What is its output?

A) 0 B) 1 C) 0 or 1 D) Undefined

3. Which logic gate produces an output of 0 if any of its inputs is 1?

A) AND gate B) OR gate C) NAND gate D) XOR gate

4. The output of an OR gate is 0. What can be said about its inputs?

A) At least one input is 1 B) All inputs are 1 C) All inputs are 0 D) Exactly one input is 0

5. Which logic gate is equivalent to a series of AND gate followed by a NOT gate?

A) OR gate B) NAND gate C) NOR gate D) XNOR gate

6. A NOR gate has an output of 1. What must be true about its inputs?

A) All inputs are 1 B) At least one input is 1 C) All inputs are 0 D) Exactly one input is 0

7. Which logic gate has an output that is the inverse of its input?

A) AND gate B) OR gate C) NOT gate D) XOR gate

8. The Boolean expression for an AND gate with inputs A and B is:

A) A + B B) A . B C) A' D) A XOR B

9. The Boolean expression for an OR gate with inputs A and B is:

A) A . B B) A + B C) A' D) A XNOR B

10. Which logic gate produces an output of 1 if the inputs are different?

A) AND gate B) OR gate C) NAND gate D) XOR gate

11. An XOR gate with inputs 1 and 0 will produce an output of:

A) 0 B) 1 C) Undefined D) Both 0 and 1

12. Which logic gate produces an output of 0 if the inputs are the same?

A) XOR gate B) AND gate C) NOR gate D) XNOR gate

13. An XNOR gate with inputs 1 and 1 will produce an output of:

A) 0 B) 1 C) Undefined D) Both 0 and 1

14. Which of the following is a universal gate, meaning any other logic gate can be constructed using only this type of gate?

A) OR gate B) AND gate C) NAND gate D) XOR gate

15. A NOR gate is considered a universal gate because:

A) It is the simplest gate B) It can be used to implement AND, OR, and NOT gates C) It requires only one input D) Its output is always 1

16. How can a NOT gate be constructed using only NAND gates?

A) Connect both inputs of a NAND gate together B) Connect one input of a NAND gate to 0 C) Connect one input of a NAND gate to 1 D) Use two NAND gates in series

17. How can an AND gate be constructed using only NOR gates?

A) Two NOR gates in series B) A NOR gate followed by a NOT gate (constructed from NOR gates) C) Three NOR gates in series D) A NOR gate with inverted inputs

18. What is the function of a half-adder circuit?

A) To add two 2-bit binary numbers B) To add two 1-bit binary numbers and produce a sum and a carry C) To subtract two 1-bit binary numbers D) To multiply two 1-bit binary numbers

19. A half-adder circuit typically uses which logic gates?

A) AND and OR gates B) XOR and AND gates C) NOT and XOR gates D) NAND and NOR gates

20. What is the output of a half-adder when the inputs are A=1 and B=0?

A) Sum=0, Carry=0 B) Sum=1, Carry=0 C) Sum=0, Carry=1 D) Sum=1, Carry=1

21. What is the output of a half-adder when the inputs are A=1 and B=1?

A) Sum=0, Carry=0 B) Sum=1, Carry=0 C) Sum=0, Carry=1 D) Sum=1, Carry=1

22. What is the function of a full-adder circuit?

A) To add two 1-bit binary numbers B) To add three 1-bit binary numbers (including a carry-in) and produce a sum and a carry-out C) To add two 2-bit binary numbers D) To perform logical OR operation on three bits

23. A full-adder can be constructed using:

A) Two half-adders and an OR gate B) One half-adder and an AND gate C) Three NOT gates D) A single XOR gate

24. What is the function of a multiplexer (MUX)?

A) To select one of several input lines and route it to a single output line B) To combine multiple input lines into one output line C) To generate a sequence of outputs D) To invert a single input line

25. How many select lines are needed for a 4-to-1 multiplexer?

A) 1 B) 2 C) 3 D) 4

26. What is the function of a demultiplexer (DEMUX)?

A) To select one of several input lines and route it to a single output line B) To route a single input line to one of several output lines, based on select inputs C) To perform logical AND operation on multiple inputs D) To generate a clock signal

27. A 1-to-8 demultiplexer requires how many select lines?

A) 1 B) 3 C) 8 D) 7

28. What is the function of a decoder?

A) To convert binary code into a specific output line B) To combine multiple inputs into a single output C) To select one of multiple inputs D) To generate a clock pulse

29. A 3-to-8 decoder has:

A) 3 input lines and 8 output lines B) 8 input lines and 3 output lines C) 3 input lines and 3 output lines D) 8 input lines and 8 output lines

30. What is the function of an encoder?

A) To convert a specific output line into a binary code B) To convert multiple inputs into a binary code C) To select one of multiple outputs D) To invert a digital signal

31. A priority encoder generates an output corresponding to the highest priority input that is active.

A) True, it prioritizes inputs automatically B) False, all inputs are treated equally C) True, but only for specific types of encoders D) False, it requires external priority logic

32. What is a flip-flop?

A) A combinational logic circuit B) A sequential logic circuit used for memory storage C) A circuit that performs arithmetic operations D) A device that amplifies signals

33. Which type of flip-flop is sensitive to the clock edge and has no race-around condition?

A) SR flip-flop B) JK flip-flop C) T flip-flop D) Master-Slave JK flip-flop

34. A D flip-flop is also known as a:

A) Set-Reset flip-flop B) Delay flip-flop C) Toggle flip-flop D) Edge-triggered flip-flop

35. What is the primary function of a register?

A) To perform arithmetic operations B) To store a group of bits C) To generate clock signals D) To amplify digital signals

36. A shift register can:

A) Store data B) Shift data bits serially or in parallel C) Perform logical operations D) All of the above

37. What is a counter in digital electronics?

A) A circuit that stores a single bit B) A circuit that generates a sequence of binary numbers C) A circuit that amplifies signals D) A circuit that performs logical AND operation

38. A ripple counter is also known as a:

A) Synchronous counter B) Asynchronous counter C) Decade counter D) Ring counter

39. In a synchronous counter, all flip-flops change state:

A) Independently B) At different times C) Simultaneously, triggered by a common clock pulse D) On alternate clock pulses

40. A decade counter counts from 0 to:

A) 7 B) 9 C) 15 D) 10

41. Which logic gate is represented by the symbol '•' in Boolean algebra?

A) OR gate B) AND gate C) NOT gate D) XOR gate

42. Which logic gate is represented by the symbol '+' in Boolean algebra?

A) AND gate B) OR gate C) NOT gate D) NAND gate

43. The output of a NAND gate with inputs 1 and 0 is:

A) 0 B) 1 C) Undefined D) Both 0 and 1

44. The output of a NOR gate with inputs 0 and 0 is:

A) 0 B) 1 C) Undefined D) Both 0 and 1

45. If a digital circuit's output is 1 only when an odd number of inputs are 1, what type of gate is it?

A) AND gate B) OR gate C) XOR gate D) XNOR gate

46. What is the primary application of basic logic gates?

A) Signal amplification B) Signal filtering C) Implementing digital logic functions D) Power regulation

47. Which of the following is NOT a fundamental logic gate?

A) AND B) OR C) NOT D) NAND

48. A simple electronic circuit that performs a specific logical operation is called a:

A) Transistor B) Resistor C) Logic gate D) Capacitor

49. Which logic gate's truth table has output 1 for all input combinations except when all inputs are 1?

A) AND gate B) OR gate C) NAND gate D) NOR gate

50. What is the characteristic property of a semiconductor diode used in simple electronic circuits?

A) It allows current to flow in both directions B) It allows current to flow only in one direction C) It blocks current flow completely D) It changes resistance based on light intensity

Basic logic gates and simple electronic circuits - Online Test

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