3.5 Fundamentals of data representation

What is a bit?

• 2 bytes

• The smallest unit of data in a computer

• 16 bits

• 1 KB

Answer explanation

A bit is the smallest unit of data in a computer, representing a binary value of 0 or 1. The other options refer to larger data units, making 'the smallest unit of data in a computer' the correct choice.

How many bits are in a byte?

• 2

• 8

• 4

• 16

Answer explanation

A byte consists of 8 bits. This is a standard unit of digital information storage, making 8 the correct answer among the choices provided.

Which of the following is a binary number?

• 11012

• 10011

• 1F2

• 9A3

Answer explanation

A binary number consists only of the digits 0 and 1. The number 10011 is the only option that meets this criterion, while 11012 contains a '2', and 1F2 and 9A3 contain non-binary characters.

Convert the binary number 1010 to decimal.

• 10

• 5

• 15

• 12

Answer explanation

To convert the binary number 1010 to decimal, calculate: (1*2^3) + (0*2^2) + (1*2^1) + (0*2^0) = 8 + 0 + 2 + 0 = 10. Thus, the correct answer is 10.

What is the base of the hexadecimal system?

• 2

• 10

• 16

• 8

Answer explanation

The hexadecimal system is a base-16 numeral system, which means it uses 16 distinct symbols (0-9 and A-F) to represent values. Therefore, the correct answer is 16.

Which of the following is a hexadecimal number?

• 8G3

• 1A2

• 10110

• 12.5

Answer explanation

Hexadecimal numbers use digits 0-9 and letters A-F. '1A2' contains valid hexadecimal characters, while '8G3' has 'G', '10110' is binary, and '12.5' is a decimal. Thus, '1A2' is the correct choice.

Convert the decimal number 63 to binary.

• 101111

• 111111

• 110111

• 100111

Answer explanation

To convert 63 to binary, divide by 2 and record the remainders. 63 ÷ 2 = 31 R1, 31 ÷ 2 = 15 R1, 15 ÷ 2 = 7 R1, 7 ÷ 2 = 3 R1, 3 ÷ 2 = 1 R1, 1 ÷ 2 = 0 R1. Reading the remainders from bottom to top gives 111111, which is the correct answer.

What is the purpose of a parity bit?

• To encode letters

• To detect errors

• To compress files

Answer explanation

A parity bit is used to detect errors in data transmission. It adds an extra bit to a binary message to ensure that the total number of 1s is even or odd, helping identify any discrepancies that may occur during transmission.

Which of these are character encoding standards? (Choose 2)

• ASCII

• Unicode

• Binary

• Hexadecimal

Answer explanation

ASCII and Unicode are both character encoding standards used to represent text in computers. ASCII encodes 128 specified characters, while Unicode supports a vast range of characters from different languages.

Which of these prefixes represents 1,024 bytes?

• KiB

• MB

• GB

• kB

Answer explanation

The prefix 'KiB' stands for kibibyte, which is equal to 1,024 bytes. In contrast, 'kB' refers to kilobyte, which is 1,000 bytes, while 'MB' and 'GB' represent megabytes and gigabytes, respectively, which are much larger units.