GATE CS Digital Logic MCQ Questions | Schoolabe

Q1easy

What is the output of an AND gate when both inputs are 1?

A)0

B)1

C)Undefined

D)Depends on previous state

Q2medium

What is the simplified form of (A + B)(A + C) using Boolean algebra?

A)A + BC

B)A + B + C

C)AB + AC

D)A + BC'

Q3easy

Which gate is called a universal gate?

A)AND

B)OR

C)NAND

D)XOR

Q4easy

What is the output of XOR gate when both inputs are 1?

A)0

B)1

C)Undefined

D)Depends on previous state

Q5medium

How many select lines are needed for a 4:1 multiplexer?

A)1

B)2

C)4

D)8

Q6easy

What is De Morgan's theorem for (A + B)'?

A)A' + B'

B)A' · B'

C)A · B

D)A + B

Q7medium

What is the sum output of a half adder when A=1 and B=1?

A)0

B)1

C)2

D)Undefined

Q8medium

How many flip-flops are needed to build a mod-8 counter?

A)2

B)3

C)4

D)8

Q9medium

What is the 2's complement representation of -5 in 4 bits?

A)1011

B)1101

C)1010

D)1111

Q10easy

Which flip-flop has no invalid state?

A)SR flip-flop

B)JK flip-flop

C)D flip-flop

D)T flip-flop

GATE CS - Digital Logic