Full Adder_Digital Logic
1. A Full Adder is used to add:
A. Two binary digits
B. Two binary digits and a carry
C. Three decimal digits
D. Two hexadecimal digits
Answer:
B
A Full Adder adds
three 1-bit inputs: A, B,
and Carry-in (Cin).
2. Full Adder has:
A. Two inputs and one output
B. Two inputs and two outputs
C. Three inputs and two outputs
D. Three inputs and one output
Answer:
C
3. Full Adder is a:
A. Sequential circuit
B. Memory device
C. Combinational circuit
D. Clocked circuit
Answer:
C
4. Inputs of a Full Adder are:
A. A, B
B. A, B, Cout
C. A, B, Cin
D. A, Cin
Answer:
C
5. Outputs of a Full Adder are:
A. Sum and Borrow
B. Difference and Carry
C. Sum and Carry
D. Carry and Overflow
Answer:
C
6. If A = 0, B = 0, Cin = 1, then output is:
A. S = 0, C = 0
B. S = 1, C = 0
C. S = 0, C = 1
D. S = 1, C = 1
Answer:
B
7. If A = 1, B = 1, Cin = 0, then output is:
A. S = 0, C = 0
B. S = 1, C = 0
C. S = 0, C = 1
D. S = 1, C = 1
Answer:
C
8. If A = 1, B = 1, Cin = 1, then output is:
A. S = 0, C = 0
B. S = 1, C = 0
C. S = 0, C = 1
D. S = 1, C = 1
Answer:
D
9. Boolean expression for SUM in Full Adder is:
A. A + B + Cin
B. A ⊕ B
C. A ⊕ B ⊕ Cin
D. AB + BC + CA
Answer:
C
10. Boolean expression for CARRY output is:
A. AB
B. AB + BCin + ACin
C. A ⊕ B
D. (A + B)Cin
Answer:
B
Carry =
majority function of A,
B, Cin.
11. Carry output is 1 when:
A. Any one input is 1
B. All inputs are 1
C. At least two inputs are 1
D. All inputs are 0
Answer:
C
12. Full Adder can be implemented using:
A. One Half Adder
B. Two Half Adders and one OR gate
C. Two XOR gates only
D. NAND gates only
Answer:
B
13. How many XOR gates are required to implement the SUM of a Full Adder?
A. 1
B. 2
C. 3
D. 4
Answer:
B
14. Which gates are required for Carry generation?
A. XOR only
B. AND only
C. AND and OR
D. NOR only
Answer:
C
15. Full Adder differs from Half Adder because Full Adder:
A. Has no carry output
B. Has carry input
C. Has one output
D. Is sequential
Answer:
B
16. Half Adder is a part of:
A. Decoder
B. Encoder
C. Full Adder
D. Multiplexer
Answer:
C
17. Full Adders are used in:
A. Multiplexers
B. Counters
C. Arithmetic Logic Unit (ALU)
D. Encoders
Answer:
C
18. Multiple Full Adders connected together form:
A. Decoder
B. Parallel Adder
C. Register
D. Counter
Answer:
B
19. Full Adder can be used for multi-bit binary addition.
A. True
B. False
Answer:
A
20. Full Adder requires a clock signal.
A. True
B. False
Answer:
B
