Computer Fundamentals MCQ – Number Systems

Here’s a set of 25 Multiple Choice Questions (MCQs) on Number Systems in Computers, covering binary, decimal, octal, hexadecimal, conversions, and arithmetic operations:


Number Systems in Computers – MCQ (50 Questions)

1. Which number system uses base 2?

a) Decimal
b) Binary
c) Octal
d) Hexadecimal

Answer: b) Binary


2. The decimal equivalent of binary number 1010 is:

a) 8
b) 10
c) 12
d) 14

Answer: b) 10


3. Which number system uses digits 0-7?

a) Binary
b) Decimal
c) Octal
d) Hexadecimal

Answer: c) Octal


4. The binary equivalent of decimal number 15 is:

a) 1110
b) 1111
c) 1010
d) 1100

Answer: b) 1111


5. Which number system uses digits 0-9 and A-F?

a) Binary
b) Decimal
c) Octal
d) Hexadecimal

Answer: d) Hexadecimal


6. The hexadecimal equivalent of binary number 1101 is:

a) A
b) B
c) D
d) E

Answer: c) D


7. The octal equivalent of decimal number 8 is:

a) 8
b) 10
c) 12
d) 16

Answer: b) 10


8. Which of the following is NOT a positional number system?

a) Binary
b) Roman numerals
c) Hexadecimal
d) Octal

Answer: b) Roman numerals


9. The decimal equivalent of hexadecimal number 1A is:

a) 16
b) 20
c) 26
d) 30

Answer: c) 26


10. The binary equivalent of octal number 7 is:

a) 110
b) 111
c) 101
d) 100

Answer: b) 111


11. The hexadecimal equivalent of decimal number 255 is:

a) FE
b) FF
c) EF
d) EE

Answer: b) FF


12. The binary number 1011 + 1101 equals:

a) 10100
b) 11000
c) 11100
d) 10000

Answer: b) 11000


13. The 1’s complement of binary number 1010 is:

a) 0101
b) 1010
c) 1101
d) 0010

Answer: a) 0101


14. The 2’s complement of binary number 1100 is:

a) 0011
b) 0100
c) 1100
d) 1011

Answer: b) 0100


15. Which number system is most commonly used in digital electronics?

a) Decimal
b) Binary
c) Octal
d) Hexadecimal

Answer: b) Binary


16. The decimal equivalent of binary number 1111 is:

a) 15
b) 16
c) 17
d) 18

Answer: a) 15


17. The octal equivalent of binary number 101010 is:

a) 42
b) 52
c) 62
d) 72

Answer: b) 52


18. The hexadecimal equivalent of binary number 10101010 is:

a) AA
b) AB
c) BA
d) BB

Answer: a) AA


19. The binary equivalent of hexadecimal number F is:

a) 1110
b) 1111
c) 1010
d) 1100

Answer: b) 1111


20. The decimal equivalent of octal number 77 is:

a) 63
b) 64
c) 65
d) 66

Answer: a) 63


21. The binary subtraction 1010 – 0110 equals:

a) 0100
b) 0110
c) 1000
d) 1100

Answer: a) 0100


22. The hexadecimal equivalent of decimal number 100 is:

a) 64
b) 65
c) 66
d) 67

Answer: a) 64


23. The octal equivalent of hexadecimal number 1F is:

a) 37
b) 47
c) 57
d) 67

Answer: a) 37


24. The binary multiplication 101 × 11 equals:

a) 1111
b) 1011
c) 1101
d) 1001

Answer: a) 1111


25. The decimal equivalent of binary number 1001 is:

a) 7
b) 8
c) 9
d) 10

Answer: c) 9