1. Which of the following is a Boolean expression for a NOT gate?
A. A⋅BA \cdot BA⋅B
B. A+BA + BA+B
C. A‾\overline{A}A
D. A⋅B‾A \cdot \overline{B}A⋅B
Answer: c) A‾\overline{A}A
Rationale: A NOT gate inverts its input, so the Boolean
expression for a NOT gate is the complement of its input.
2. What is the output of an AND gate if both inputs are 1?
A. 1
B. 0
C. Undefined
D. Always 0
,Answer: a) 1
Rationale: An AND gate outputs 1 only if both inputs are 1.
Otherwise, the output is 0.
3. Which logic gate is used to implement the XOR operation?
A. AND gate
B. OR gate
C. NOR gate
D. Exclusive OR (XOR) gate
Answer: d) Exclusive OR (XOR) gate
Rationale: The XOR gate outputs 1 when the number of 1's in the
input is odd.
4. A truth table has 3 variables. How many rows will the truth
table have?
A. 4
,B. 6
C. 8
D. 16
Answer: c) 8
Rationale: A truth table for n variables has 2n2^n2n rows. For 3
variables, 23=82^3 = 823=8.
5. What is the Boolean expression for the NAND gate?
A. A⋅B‾\overline{A \cdot B}A⋅B
B. A+BA + BA+B
C. A+B‾\overline{A + B}A+B
D. A⋅BA \cdot BA⋅B
Answer: a) A⋅B‾\overline{A \cdot B}A⋅B
Rationale: The NAND gate is the complement of the AND gate.
Its output is A⋅B‾\overline{A \cdot B}A⋅B.
, 6. Which of the following logic gates is considered a universal
gate?
A. AND
B. OR
C. NAND
D. XOR
Answer: c) NAND
Rationale: The NAND gate is considered a universal gate because
it can be used to implement any other gate.
7. What is the binary equivalent of the decimal number 14?
A. 1110
B. 1101
C. 1011
D. 1000
Answer: a) 1110
A. A⋅BA \cdot BA⋅B
B. A+BA + BA+B
C. A‾\overline{A}A
D. A⋅B‾A \cdot \overline{B}A⋅B
Answer: c) A‾\overline{A}A
Rationale: A NOT gate inverts its input, so the Boolean
expression for a NOT gate is the complement of its input.
2. What is the output of an AND gate if both inputs are 1?
A. 1
B. 0
C. Undefined
D. Always 0
,Answer: a) 1
Rationale: An AND gate outputs 1 only if both inputs are 1.
Otherwise, the output is 0.
3. Which logic gate is used to implement the XOR operation?
A. AND gate
B. OR gate
C. NOR gate
D. Exclusive OR (XOR) gate
Answer: d) Exclusive OR (XOR) gate
Rationale: The XOR gate outputs 1 when the number of 1's in the
input is odd.
4. A truth table has 3 variables. How many rows will the truth
table have?
A. 4
,B. 6
C. 8
D. 16
Answer: c) 8
Rationale: A truth table for n variables has 2n2^n2n rows. For 3
variables, 23=82^3 = 823=8.
5. What is the Boolean expression for the NAND gate?
A. A⋅B‾\overline{A \cdot B}A⋅B
B. A+BA + BA+B
C. A+B‾\overline{A + B}A+B
D. A⋅BA \cdot BA⋅B
Answer: a) A⋅B‾\overline{A \cdot B}A⋅B
Rationale: The NAND gate is the complement of the AND gate.
Its output is A⋅B‾\overline{A \cdot B}A⋅B.
, 6. Which of the following logic gates is considered a universal
gate?
A. AND
B. OR
C. NAND
D. XOR
Answer: c) NAND
Rationale: The NAND gate is considered a universal gate because
it can be used to implement any other gate.
7. What is the binary equivalent of the decimal number 14?
A. 1110
B. 1101
C. 1011
D. 1000
Answer: a) 1110
