BEE Digital Logic and Design 5

Question 1

In two's complement representation using 8 bits, what is the decimal value of 1111 1111?

Accepted Answer

-1

Answer

In 8-bit two's complement, 11111111 represents -1 because inverting gives 00000000 and adding 1 gives 00000001=+1, confirming -1.

Question 2

What is a race condition in a sequential circuit?

Accepted Answer

When the next state depends on the order in which multiple variables change simultaneously

Answer

A race condition occurs when multiple state variables change simultaneously and the final state depends on which variable changes first, potentially causing incorrect behavior.

Question 3

Which Boolean expression represents the output of an SR NOR latch when S=1, R=0 (assuming it was previously reset)?

Accepted Answer

Q=1, Q'=0

Answer

With S=1 (Set) and R=0 in an SR NOR latch, the output is set: Q=1 and Q'=0.

Question 4

What is the purpose of a priority encoder?

Accepted Answer

To generate a binary code corresponding to the highest-priority active input

Answer

A priority encoder accepts multiple inputs and outputs a binary code representing the highest-priority (typically highest-numbered) active input, resolving conflicts when multiple inputs are asserted.

Question 5

How many product terms can a 4-variable K-map group of 4 adjacent cells eliminate?

Accepted Answer

2 variables

Answer

A group of 4 cells (2²) in a K-map eliminates 2 variables from the product term, leaving a 2-literal expression.

BEE - Bachelor of Electrical Engineering Practice Test

BEE - Bachelor of Electrical Engineering Practice Test

BEE Digital Logic and Design 5