Data representation and data types

Question 1

What is a bit?

Answer 1

A bit is a single digit that can be 1 or 0 (on or off)

Question 2

What is a nibble?

Answer 2

A nibble is an arrangement of 4 bits, with 16 possible combinations.

Question 3

What is a byte?

Answer 3

A byte is an arrangement of 8 bits, with 128 possible combinations.

Question 4

What is a word in computing?

Answer 4

A word is the amount of data that a CPU can process within a certain amount of time. It can be 64 or 128 bits long.

Question 5

How many bits are in a byte

Answer 5

8 bits

Question 6

How many bits are in a nibble

Answer 6

4 bits

Question 7

How many bytes are in a Kilobyte (KB)

Answer 7

1024 bytes

Question 8

How many KB are in a megabyte (MB)?

Answer 8

1024 KB

Question 9

How many MB are in a gigabyte (GB)?

Answer 9

1024 MB

Question 10

How many GB are in a terabyte (TB)?

Answer 10

1024 GB

Question 11

How many TB are in a petabyte (PB)?

Answer 11

1024 TB

Question 12

What is the difference between Mb and MB?

Answer 12

Mb stands for megabits, while MB stands for megabytes. To convert Mb to MB, divide by 8.

Question 13

What is a character data type?

Answer 13

A single letter, digit, or punctuation mark (e.g., ‘A’, ‘4’, ‘!’).

Question 14

What is a string

Answer 14

A sequence of characters (e.g., “computer”, “science”).

Question 15

What is an unsigned integer?

Answer 15

A whole number that is always positive (e.g., 42, 11, 1).

Question 16

What is a signed integer?

Answer 16

A whole number that can be positive or negative (e.g., 12, -18, 0).

Question 17

What is a real number

Answer 17

A fractional or decimal number(e.g., 15.6, -12.25)

Question 18

What is a boolean

Answer 18

A data type that represents either true or false (1 or 0)

Question 19

How do computers represent characters

Answer 19

Each character is mapped to a binary number for standardized communication between systems.

Question 20

What is ASCII

Answer 20

A character encoding system that uses 8 buts to represent 255 characters, mainly in the English language

Question 21

What is Unicode

Answer 21

A character encoding system that supports multiple languages and symbols it currently uses 21 bits (3 bytes)

Question 22

What is the amin difference between ASCII and Unicode

Answer 22

ASCII can only represent 255 characters, while Unicode supports a vast range of characters from different languages.

Question 23

Why do computers use binary instead of decimal

Answer 23

Computers store data using 1s and 0s because they represent electrical on/off states

Question 24

What is the binary representation of the number 3

Answer 24

00000011

Question 25

What is an advantage of binary

Answer 25

It is easy for computers to understand since it represents electrical signals (on/off)

Question 26

What is a disadvantage of binary

Answer 26

It is difficult for humans to interpret without conversion

Question 28

What is an advantage of hexadecimal

Answer 28

It can store larger data efficiently since it has more digits (0-9, A-F)

Question 29

What is a disadvantage of hexadecimal?

Answer 29

It can be harder to understand and convert compared to binary or decimal

Question 30

What is sign and magnitude in binary

Answer 30

A way to represent positive and negative numbers using the leftmost bit as the sign bit

Question 31

What is two’s complement?

Answer 31

A method to represent negative numbers in binary by inverting bits and adding 1

Question 32

What are 2 components of a floating point number

Answer 32

The mantissa (significant digits) and the exponent (power of 10)

Question 33

What is truncation?

Answer 33

removing extra bits beyond a certain point without rounding.

Truncation Example
0.1011011 and truncate it to 4 bits after the decimal point.

Original number: 0.1011011
Truncated to 4 bits: 0.1011
Truncation error: The removed bits (011) represent a small lost value.
If converted to decimal:

Original: 0.1011011 (≈ 0.7109375 in decimal)
Truncated: 0.1011 (≈ 0.6875 in decimal)
Error: 0.7109375 - 0.6875 = 0.0234375

Question 34

What is rounding in binary?

Answer 34

Adjusting the last digit based on the next digit (round up if 1, down if 0)

Rounding example
Original number: 0.1011011
Looking at the 5th bit (which is 0)
Since it’s less than 1, we round down
Rounded result: 0.1011 (same as truncation in this case)
If the 5th bit had been 1 (e.g., 0.1011111), we would round up to 0.1100 instead.

Question 35

Which is usually more accurate: Truncation or rounding

Answer 35

Rounding, because it minimizes bias