The carry propagation delay in 4-bit full-adder circuits: is cumulative for each

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Question
The carry propagation delay in 4-bit full-adder circuits:
Options
A. is cumulative for each stage and limits the speed at which arithmetic operations are performed
B. is normally not a consideration because the delays are usually in the nanosecond range
C. decreases in direct ratio to the total number of full-adder stages
D. increases in direct ratio to the total number of full-adder stages, but is not a factor in limiting the speed of arithmetic operations

Correct Answer

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

Digital Arithmetic Operations and Circuits problems

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1. Determine the two's-complement of each binary number.
00110 00011 11101
Options
A. 11001 11100 00010
B. 00111 00010 00010
C. 00110 00011 11101
D. 11010 11101 00011

4. 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:
Options
A. ignore the lowest order code group because 0000 is a valid code group and prefix the carry with three zeros
B. add 0110 to both code groups to validate the carry from the lowest order code group
C. disregard the carry and add 0110 to the lowest order code group
D. add 0110 to the lowest order code group because a carry was generated and then prefix the carry with three zeros

6. Which of the following is correct for full adders?
Options
A. Full adders have the capability of directly adding decimal numbers.
B. Full adders are used to make half adders.
C. Full adders are limited to two inputs since there are only two binary digits.
D. In a parallel full adder, the first stage may be a half adder.

7. Convert each of the decimal numbers to 8-bit two's-complement form and then perform subtraction by taking the two's-complement and adding.
Options
A. 0001 0011
B. 0000 1110
C. 0010 1110
D. 1110 0000

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