Number Systems: 45 MCQs with answers

All 45 multiple-choice questions from this kit, free and with no sign-up.

Warm-up · 27 questions

Q1. Which of the following is the base of the hexadecimal number system?

Beginner
A 2 B 16 C 8 D 10
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16

Hexadecimal is a base-16 number system, using digits 0-9 and letters A-F.

Q2. What is the binary equivalent of the decimal number 10?

Beginner
A 1010 B 1100 C 1110 D 1001
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1010

Decimal 10 in binary is 1010 because $1 \times 2^3 + 0 \times 2^2 + 1 \times 2^1 + 0 \times 2^0 = 8 + 0 + 2 + 0 = 10$.

Q3. In sign-magnitude representation, what does the leftmost bit represent?

Beginner
A The base of the number system B The parity of the number C The sign of the number (0 for positive, 1 for negative) D The magnitude of the number
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The sign of the number (0 for positive, 1 for negative)

In sign-magnitude representation, the most significant bit (leftmost) is the sign bit: 0 indicates positive and 1 indicates negative. The remaining bits represent the magnitude.

Q4. Which of the following is a fixed-point representation?

Beginner
A Integer representation B Scientific notation C Floating point D Sign-magnitude
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Integer representation

Fixed-point representation has a fixed number of digits after the decimal point. Integer representation is a type of fixed-point where the decimal point is fixed at the right end.

Q5. Which character encoding standard is capable of representing characters from almost all writing systems of the world?

Beginner
A BCD B EBCDIC C ASCII D Unicode
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Unicode

Unicode is a universal character encoding standard designed to support the characters of all major world languages, unlike ASCII or EBCDIC which are limited.

Q6. What is the hexadecimal equivalent of the binary number 1010?

Beginner
A A B D C B D C
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A

Binary 1010 equals decimal 10, which is represented as A in hexadecimal.

Q7. Which of the following is true about ASCII?

Beginner
A It is a 16-bit code B It is used only for numeric data C It is a 4-bit code D It is a 7-bit code
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It is a 7-bit code

Standard ASCII is a 7-bit character encoding, allowing 128 different characters. Extended ASCII uses 8 bits.

Q8. The binary number system uses only two digits: 0 and 1.

Beginner
A True B False
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True

The binary system is base-2 and uses only the digits 0 and 1.

Q9. What is the base of the binary number system?

Beginner
A 2 B 16 C 10 D 8
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2

The binary number system is based on 2, which means it uses two digits: 0 and 1.

Q10. Which of the following is a valid representation of the decimal number 5 in binary?

Beginner
A 101 B 110 C 100 D 111
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101

The binary representation of the decimal number 5 is 101.

Q11. What does ASCII stand for?

Beginner
A American Standard Code for Internet Interaction B Applied Standard Code for Information Interchange C Advanced Standard Code for Information Interchange D American Standard Code for Information Interchange
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American Standard Code for Information Interchange

ASCII stands for American Standard Code for Information Interchange, which is a character encoding standard.

Q12. What is the decimal equivalent of the binary number 1101?

Beginner
A 15 B 13 C 12 D 14
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13

The binary number 1101 is equal to the decimal number 13.

Q13. Which of the following is a characteristic of the octal number system?

Beginner
A Uses digits from 0 to 7 B Uses digits from 0 to 6 C Uses digits from 0 to 9 D Uses digits from 0 to 15
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Uses digits from 0 to 7

The octal number system uses digits from 0 to 7.

Q14. In which number system is the digit 'F' used?

Beginner
A Hexadecimal B Decimal C Binary D Octal
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Hexadecimal

The digit 'F' is used in the hexadecimal number system, representing the decimal value 15.

Q15. What is the 2's complement of the binary number 0010?

Beginner
A 0010 B 1101 C 0001 D 1110
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1110

The 2's complement of 0010 is 1110, which is obtained by inverting the bits and adding 1.

Q16. Which of the following represents a character encoding scheme?

Beginner
A Floating Point B Fixed Point C Binary Coded Decimal (BCD) D Two's Complement
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Binary Coded Decimal (BCD)

Binary Coded Decimal (BCD) is a character encoding scheme that represents decimal numbers in binary.

Q17. What is a characteristic of the hexadecimal number system?

Beginner
A Base 16 B Base 8 C Base 2 D Base 10
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Base 16

The hexadecimal number system is based on 16, using digits 0-9 and letters A-F.

Q18. What is the decimal equivalent of the octal number 10?

Beginner
A 8 B 16 C 10 D 12
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8

The octal number 10 is equal to the decimal number 8.

Q19. What is the base of the decimal number system?

Beginner
A 16 B 10 C 8 D 2
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10

The decimal number system is based on 10, using digits from 0 to 9.

Q20. Which of the following is a valid binary number?

Beginner
A 1021 B ABC C 123 D 1101
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1101

The binary number system only uses the digits 0 and 1, making '1101' a valid binary number.

Q21. What is the hexadecimal equivalent of the decimal number 15?

Beginner
A 1F B E C 10 D F
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F

In the hexadecimal system, the decimal number 15 is represented as 'F'.

Q22. Which of the following is a characteristic of the binary number system?

Beginner
A Uses digits 0-7 B Uses digits 0-F C Uses digits 0 and 1 D Uses digits 0-9
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Uses digits 0 and 1

The binary number system exclusively uses the digits 0 and 1.

Q23. What does BCD stand for in number representation?

Beginner
A Base Coded Decimal B Binary Character Decimal C Binary Coded Decimal D Binary Coded Digit
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Binary Coded Decimal

BCD stands for Binary Coded Decimal, which represents decimal numbers in binary form.

Q24. What is the decimal equivalent of the binary number 1010?

Beginner
A 14 B 10 C 8 D 12
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10

The binary number '1010' is equal to the decimal number 10.

Q25. Which of the following is NOT a valid character encoding scheme?

Beginner
A UTF-16 B BCD C ASCII D UTF-8
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BCD

BCD is not a character encoding scheme; it is a way to represent decimal numbers in binary.

Q26. What is the base of the octal number system?

Beginner
A 8 B 16 C 2 D 10
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8

The octal number system is based on 8, using digits from 0 to 7.

Q27. In which number system is the digit 'A' used?

Beginner
A Binary B Decimal C Hexadecimal D Octal
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Hexadecimal

The digit 'A' is used in the hexadecimal number system to represent the decimal value 10.

Building up · 17 questions

Q28. Which of the following is NOT a valid BCD code?

Intermediate
A 1010 B 0000 C 0111 D 1001
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1010

BCD (Binary Coded Decimal) uses only the binary patterns 0000 to 1001 to represent decimal digits 0-9. The pattern 1010 represents decimal 10, which is not a single decimal digit, so it is invalid in BCD.

Q29. What is the 1's complement of the binary number 1010?

Intermediate
A 0101 B 1100 C 0110 D 1011
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0101

The 1's complement is obtained by flipping each bit: 1 becomes 0 and 0 becomes 1. So 1010 becomes 0101.

Q30. What is the 2's complement of the binary number 1100?

Intermediate
A 1101 B 0011 C 0100 D 0010
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0100

The 2's complement is found by taking the 1's complement (0011) and adding 1, giving 0100.

Q31. What is the decimal equivalent of the octal number 17?

Intermediate
A 15 B 17 C 16 D 14
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15

Octal 17 equals $1 \times 8^1 + 7 \times 8^0 = 8 + 7 = 15$ in decimal.

Q32. What is an error code in the context of digital systems?

Intermediate
A A code that corrects errors automatically B A code that represents negative numbers C A code used to detect and possibly correct errors in data transmission or storage D A code that converts between number systems
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A code used to detect and possibly correct errors in data transmission or storage

Error codes are used to detect and correct errors that may occur during data transmission or storage. Examples include parity bits and Hamming codes.

Q33. In floating-point representation, what does the exponent indicate?

Intermediate
A The position of the binary point B The sign of the number C The precision of the number D The base of the number system
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The position of the binary point

In floating-point representation, the exponent indicates the position of the binary point (or decimal point) relative to the mantissa, allowing representation of very large or very small numbers.

Q34. In 1's complement representation, there are two representations for zero: +0 and -0.

Intermediate
A True B False
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True

In 1's complement, positive zero is represented as all 0s (e.g., 0000) and negative zero as all 1s (e.g., 1111), leading to two distinct representations for zero.

Q35. What is the binary representation of the decimal number 13?

Intermediate
A 1011 B 1110 C 1100 D 1101
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1101

The binary representation of the decimal number 13 is obtained by converting it to binary, which results in 1101.

Q36. Which of the following number systems uses base 16?

Intermediate
A Hexadecimal B Decimal C Binary D Octal
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Hexadecimal

The hexadecimal number system uses base 16, which includes digits from 0 to 9 and letters A to F.

Q37. In the context of character encoding, what does UTF-8 stand for?

Intermediate
A Universal Transformation Format - 8 bits B Universal Text Format - 8 bits C Unicode Text Format - 8 bits D Unicode Transformation Format - 8 bits
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Unicode Transformation Format - 8 bits

UTF-8 stands for Unicode Transformation Format - 8 bits, which is a variable-width character encoding.

Q38. What is the 1's complement of the binary number 0110?

Intermediate
A 0011 B 0100 C 1001 D 1010
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1010

The 1's complement of a binary number is obtained by flipping all bits. For 0110, the 1's complement is 1001.

Q39. Which of the following is a valid representation of the decimal number 7 in BCD?

Intermediate
A 0000 B 0110 C 1110 D 0111
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0111

In Binary-Coded Decimal (BCD), the decimal number 7 is represented as 0111.

Q40. What is the decimal equivalent of the hexadecimal number 2F?

Intermediate
A 31 B 29 C 47 D 50
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47

The hexadecimal number 2F converts to decimal as follows: $2 \times 16^1 + 15 \times 16^0 = 32 + 15 = 47$.

Q41. In floating-point representation, what does the significand represent?

Intermediate
A The base part B The value of the number C The exponent part D The sign of the number
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The value of the number

In floating-point representation, the significand (or mantissa) represents the value of the number, while the exponent scales it.

Q42. What is the 2's complement of the binary number 1011?

Intermediate
A 0110 B 0101 C 1101 D 1001
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1101

To find the 2's complement, first take the 1's complement (0100) and add 1, resulting in 1101.

Q43. Which of the following correctly describes the relationship between binary and decimal systems?

Intermediate
A Binary is base 8, while decimal is base 10. B Both binary and decimal are base 10. C Binary is base 10, while decimal is base 2. D Binary is base 2, while decimal is base 10.
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Binary is base 2, while decimal is base 10.

Binary is a base 2 number system, while the decimal system is base 10.

Q44. What is the octal equivalent of the binary number 101101?

Intermediate
A 45 B 55 C 63 D 57
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57

To convert binary 101101 to octal, group the binary digits in sets of three from the right: 101 101, which is 5 7 in octal.

Topper level · 1 questions

Q45. What is the 2's complement representation of the decimal number -5 in 4 bits?

Advanced
A 1010 B 1110 C 1101 D 1011
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1011

To represent -5 in 4-bit 2's complement: first write +5 as 0101, then take 1's complement (1010) and add 1, giving 1011.

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