Page 45 - computer science (868) class 11
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20. Subtract (1B7) - (8D27) using
16
16
a. 15’s complement method
b. 16’s complement method
Ans. a. 15’s complement of 8D27 is 72D8 +1
Adding 1B7 and 72D8, we get 1 B 7
15’s complement of 748F is 8B70 + 7 2 D 8
(-8B70) 16 7 4 8 F
b. 15’s complement of 8D27 is 72D8 +1 +1
16’s complement of 72D8 is 72D9 1 B 7
Adding 1B7 and 72D9, we get 7490 + 7 2 D 9
15’s complement of 7490 is 8B6F 7 4 9 0
16’s complement of 8B6F is 8B70
(-8B70) 16
Unsolved Questions
A. Tick ( ) the correct option:
1. Which of these is the base of an octal number system?
a. 2 b. 8
c. 16 d. 10
2. The binary equivalent of the decimal number 9 is ………………… .
a. 1000 b. 1010
c. 1001 d. 1011
3. Which of the following is not an octal number?
a. 827 b. 567
c. 777 d. 245.27
4. To express a hexadecimal number to its binary equivalent, each hexadecimal digit is expressed into ………………… .
a. 2 bits form b. 3 bits form
c. 4 bits form d. 15 bits form
5. The octal equivalent of decimal number 10 is ………………… .
a. 1010 b. A
c. 0010 d. 12
6. Adding binary digits 1+1+1 will result in ………………….
a. Sum 1, Carry 0 b. Sum 0, Carry 1
c. Sum 3, Carry 0 d. Sum 1, Carry 1
7. Adding octal digits 6+7 will result in ………………… .
a. Sum 13, Carry 0 b. Sum 5, Carry 1
c. Sum 1, Carry 5 d. Sum 7, Carry 1
8. 15’s complement of hexadecimal number AB51 is ………………… .
a. 54AE b. 55AF
c. 65BF d. 65BE
9. In decimal to binary conversion, the first remainder is called ………………… .
a. MSB b. FSB
c. LSB d. RSB
10. Subtracting 1-0 in binary number system gives ………………… .
a. Result 1, borrow 0 b. Result -1, borrow 1
c. Result 1, borrow 1 d. Result 0, borrow 1
43
Numbers 43

