Digital Arithmetic Operations and Circuits MCQs

Question 1

Convert each of the decimal numbers to two's-complement form and perform the addition in binary. +13 –10 add –7 add +15

Accepted Answer

0000 0110 0000 0101

Answer

0001 0100 0000 0101

Answer

0000 0110 0001 1001

Answer

1111 0110 1111 0101

Question 2

The carry propagation delay in full-adder circuits:

Accepted Answer

is cumulative for each stage and limits the speed at which arithmetic operations are performed.

Answer

is normally not a consideration because the delays are usually in the nanosecond range.

Answer

decreases in a direct ratio to the total number of FA stages.

Answer

increases in a direct ratio to the total number of FA stages but is not a factor in limiting the speed of arithmetic operations.

Question 3

What is the difference between a full-adder and a half-adder?

Accepted Answer

Full-adder has a carry-in.

Answer

Half-adder has a carry-in.

Answer

Half-adder does not have a carry-out.

Answer

Full-adder does not have a carry-out.

Question 4

The summing outputs of a half- or full-adder are designated by which Greek symbol?

Accepted Answer

sigma

Answer

omega

Answer

theta

Answer

lambda

Question 5

The BCD addition of 910 and 710 will give initial code groups of 1001 + 0111. Addition of these groups generates a carry to the next higher position. The correct solution to this problem would be to:

Accepted Answer

add 0110 to the lowest order code group because a carry was generated and then prefix the carry with three zeros

Answer

ignore the lowest order code group because 0000 is a valid code group and prefix the carry with three zeros

Answer

add 0110 to both code groups to validate the carry from the lowest order code group

Answer

disregard the carry and add 0110 to the lowest order code group

Question 6

Why is a fast-look-ahead carry circuit used in the 7483 4-bit full-adder?

Accepted Answer

to speed up the circuit

Answer

to decrease the cost

Answer

to make it smaller

Answer

to slow down the circuit

Question 7

Find the 2's complement of –1101102.

Accepted Answer

0010102

Answer

1101002

Answer

1010102

Answer

0010012

Question 8

What logic function is the sum output of a half-adder?

Accepted Answer

exclusive-OR

Answer

AND

Answer

exclusive-NOR

Answer

NAND

Question 9

The binary adder circuit is designed to add ________ binary numbers at the same time.

Accepted Answer

2

Answer

4

Answer

6

Answer

8