Computer Fundamentals Multiple choice Questions and Answers on The Hexadecimal Number System for Freshers

1. What does the symbol D represent in a hexadecimal number system?

a) 8
b) 16
c) 13
d) 14

Answer: c

Explanation: The symbols A, B, C, D, E and F represent 10, 11, 12, 13, 14 and 15 respectively in a hexadecimal system. This system comprises of 15 numbers in total: digits from 0-9 and symbols from A to F.

2. ABC is a valid hexadecimal number.

a) True
b) False

Answer: a

Explanation: In a hexadecimal number system, alphabets are used for the representation of numbers from 10 to 15. Here, A represents 10, B represents 11 and C represents 12. Therefore, it is a valid hexadecimal number.

3. The maximum number of bits sufficient to represent a hexadecimal number in binary:

a) 4
b) 3
c) 7
d) 8

Answer: a

Explanation: The hexadecimal number system comprises of only 15 symbols: 10 digits and 5 symbols. Hence, three bits (24 = 16 ) are sufficient to represent any hexadecimal number in the binary format.

4. The binary number 1110 in hexadecimal format is _____________

a) 6
b) E
c) 14
d) 15

Answer: b

Explanation: Certain binary to hexadecimal representations are :
1010=A
1011=B
1100=C
1101=D
1110=E
1111=F.

5. Convert (52)16 into its decimal equivalent.

a) 28
b) 83
c) 80
d) 82

Answer: d

Explanation: To convert a hexadecimal number to decimal number:
161 * 5 + 160 * 2 = 80 + 2 = 82
Hence, the decimal equivalent is 82.

6. The hexadecimal equivalent of the binary number (0010010100)2 is :

a) 0B4
b) 0A4
c) 224
d) 0114

Answer: c

Explanation: To obtain the octal equivalent, we take numbers in groups of 3, from right to left as :

7. Hexadecimal Addition of (3A5)16 and (1B2)16 will give :

a) 165
b) 185
c) 815
d) 516

Answer: a

Explanation: Octal subtraction is done as follows:
3A5
+ 1B2
________
557
In hexadecimal addition of alphabets, we add the corresponding numbers they represent and then subtract the result from 16, then generate a carry of 1 to the next set of numbers.
Here, 5+2=7
A+B=10+11=21-16=5
3+1+1(carry)=5.

8. The 2’s complement of 10.11 :

a) 10
b) 0.010
c) 01.01
d) 10.01

Answer: a

Explanation: The 1’s complement of a number is obtained by reversing the bits with value 1 to 0 and the bits with value 0 to 1. Here, 10.11 gets converted to 01.00 in its 1’s complement format. Further, to convert 1’s complement into 2’s, we add 1 to the result. Here, 01.00+1=10.00.

9. Convert (6532)8 to hexadecimal.

a) A01
b) A02
c) B01
d) C01

Answer: c

Explanation: To convert octal to hexadecimal, we first write binary format of the number and then make groups of 4 bits from right to left, as follows:

 6   5   3   2
110 101 011 010   (octal -> binary)
1101  0101  1010  ( groups of 4)
 D    5      A    ( hexadecimal equivalent)

Therefore, the hexadecimal equivalent is (D5A)16.

10. What do we call the point(decimal) in any hexadecimal number of the form 111.A3?

a) radix
b) hexadecimal point
c) decimal
d) octal point

Answer: b

Explanation: The decimal is often referred to as the hexadecimal point in hexadecimal representation of numbers.
It is referred to as the octal point in octal numbers.