BEE Digital Logic and Systems 5

Question 1

Which Boolean identity represents De Morgan's theorem for a two-input AND gate?

Accepted Answer

(AB)' = A' + B'

Answer

De Morgan's theorem states that the complement of a product equals the sum of complements: (AB)' = A' + B'.

Question 2

What is the main advantage of a carry look-ahead adder over a ripple carry adder?

Accepted Answer

Computes carries in parallel, reducing addition time

Answer

Carry look-ahead adders generate and propagate carry signals in parallel rather than waiting for them to ripple through each stage.

Question 3

A full adder differs from a half adder in that it:

Accepted Answer

Includes a carry-in input

Answer

A full adder has three inputs — A, B, and carry-in (Cin) — allowing it to be cascaded to build multi-bit adders.

Question 4

Which state minimization concept groups equivalent states in a finite state machine to reduce hardware?

Accepted Answer

State reduction (state equivalence)

Answer

State reduction identifies and merges states that produce identical outputs for all input combinations, minimizing the number of flip-flops needed.

Question 5

In Boolean algebra, which law states that A + AB = A?

Accepted Answer

Absorption law

Answer

The absorption law states A + AB = A because A already implies AB, so the redundant term AB is absorbed.

BEE - Bachelor of Electrical Engineering Practice Test