Digital Electronics-Digital Arithmetic Operations and Circuits
Digital Electronics-Digital Arithmetic Operations and Circuits
11. Adding in binary, a decimal 26 + 27 will produce a sum of:
- 111010
- 110110
- 110101
- 101011
12. Convert each of the following signed binary numbers (two's-complement) to a signed decimal number.
00000101 11111100 11111000
00000101 11111100 11111000
- –5 +4 +8
- +5 –4 –8
- –5 +252 +248
- +5 –252 –248
14. If [A] = 1011 1010, [B] = 0011 0110, and [C] = [A] • [B], what is [C 4..2] in decimal?
- 1
- 2
- 3
- 4
15. Using 4-bit adders to create a 1See Section 6-bit adder:
- requires 16 adders.
- requires 4 adders.
- requires the carry-out of the less significant adder to be connected to the carry-in of the next significant adder.
- requires 4 adders and the connection of the carry out of the less significant adder to the carry-in of the next significant adder.
16. When performing subtraction by addition in the 2's-complement system:
- the minuend and the subtrahend are both changed to the 2's-complement.
- the minuend is changed to 2's-complement and the subtrahend is left in its original form.
- the minuend is left in its original form and the subtrahend is changed to its 2's-complement.
- the minuend and subtrahend are both left in their original form.
17. The two's-complement system is to be used to add the signed numbers 11110010 and 11110011. Determine, in decimal, the sign and value of each number and their sum.
- –14 and –13, –27
- –113 and –114, 227
- –27 and –13, 40
- –11 and –16, –27
19. One way to make a four-bit adder perform subtraction is by:
- inverting the output.
- inverting the carry-in.
- inverting the B inputs.
- grounding the B inputs.
20. What is the most important operation in binary-coded decimal (BCD) arithmetic?
- addition
- subtraction
- multiplication
- division