Computer Fundamentals Multiple choice Questions and Answers on Sign Magnitude for Freshers

1. __________________ is a straightforward method of representing positive and negative numbers.

a) Radix
b) Complement
c) Sign Magnitude
d) Encode

Answer: c

Explanation: Sign Magnitude is used for the representation of positive and negative numbers. If the leftmost digit is 0, the number is positive. If the leftmost digit is 1, the number is negative.

2. The additive inverse of a number is the number which when added to the original number gives 1 as a result.

a) True
b) False

Answer: b

Explanation: Additive Inverse of a number is the number which gives 0 and not 1 when added to the original number. e.g. number=45, additive inverse =-45, after addition they give 0.

3. The 1’s complement of 1 in 4 bits is __________

a) 0001
b) 0
c) 1001
d) 1110

Answer: d

Explanation: 1’s complement is obtained by reversing the bits from 0 to 1 and vice-versa. Binary of 1 is : 0001 and 1’s complement is : 1110.

4. The binary number 111 in its 2’s complement form is ____________

a) 010
b) 001
c) 000
d) 111

Answer: b

Explanation: 2’s complement is obtained by adding 1 to the 1’s complement. 1’s complement of 111: 000 and 2’s complement:001.

5. The sign magnitude representation of -9 is ___________

a) 00001001
b) 11111001
c) 10001001
d) 11001

Answer: c

Explanation: In case of a negative number, the leftmost digit is 1 if the number is negative. Therefore, +9=00001001 and -9=10001001. Similarly for all other negative numbers.

6. If you are given a word of size n bits, the range of 2’s complement of binary numbers is ________

a) -2n+1 to +2n+1
b) -2n-1 to +2n-1
c) -2n-1 to +2n+1
d) -2n-1 to +2n-1-1

Answer: d

Explanation: 2’s complement is obtained by adding 1 to the 1’s complement. For e.g. 5 :0101 and 1’s complement=1010 and 2’s complement=1011.

7. In both signed magnitude and 2’s complement , positive and negative numbers are separated using ______________

a) LSB
b) MSB
c) 0
d) 1

Answer: b

Explanation: The positive and negative numbers are separated using the MSB. MSB is the Most Significant Bit. MSB is the leftmost bit. e.g. If 1000 is the number then 1 is the most significant bit.

8. Single Precision format comprises of _________ bits.

a) 4
b) 8
c) 16
d) 32

Answer: d

Explanation: The single precision format comprises of 32-bits. It has 1 sign bit, 8 bits for exponent and 23 for the mantissa.

9. If m is the 2’s complement and n is the binary number, then ______________

a) m=n’
b) m=n’+1
c) m=n’-1
d) m=n

Answer: b

Explanation: 2’s complement is simply obtained by addition of 1. So if n is the number and we take the 2’s complement, add 1 to it, we get the 2’s complement. Therefore, m=n’+1.

10. The possible number of bit patterns with 8 bits ________________

a) 128
b) 8
c) 24
d) 256

Answer: d

Explanation: The total number of patterns that can be formed using n-bits are 2n. Here, possible patterns are: 28=256.