BEE BEE Bachelor of Electrical Engineering Digital Logic and Design Questions and Answers 3

Question 1

What is the propagation delay disadvantage of a ripple carry adder compared to a carry lookahead adder?

Accepted Answer

Its delay grows linearly with bit width

Answer

It uses more gates

Answer

It cannot handle subtraction

Answer

It requires more flip-flops

Question 2

Which state encoding technique assigns adjacent states codes that differ by only one bit?

Accepted Answer

Gray encoding

Answer

Binary encoding

Answer

One-hot encoding

Answer

Priority encoding

Question 3

In a Moore finite state machine, when does the output change?

Accepted Answer

Only on clock edges when state changes

Answer

Immediately when input changes

Answer

Asynchronously with input transitions

Answer

During the setup time window

Question 4

What is the purpose of a don't-care condition in a truth table?

Accepted Answer

To allow flexibility in minimization for unused input combinations

Answer

To indicate an error state

Answer

To represent high-impedance output

Answer

To define default output values

Question 5

How many select lines are needed for an 8-to-1 multiplexer?

Accepted Answer

3

Answer

2

Answer

4

Answer

8

Question 6

What does the excitation table of a JK flip-flop show for a transition from Q=0 to Q=1?

Accepted Answer

J=1, K=X

Answer

J=0, K=1

Answer

J=1, K=0

Answer

J=X, K=1