Computer Science (Y8) End of Years Revision

Question 1

How many digits does the binary system use? What are they?

Answer 1

2 (0 and 1)

Question 2

How many digits does the denary number system use? What are they?

Answer 2

10 (1, 2, 3, 4, 5, 6, 7, 8, 9 and 0)

Question 3

What are the placeholder values for an 8-bit binary number?

Answer 3

1,2,4,8,16,32,64,128

Question 4

Convert the binary number 01001110 to a denary number

Answer 4

78

Question 5

Convert the binary number 00011111 to a denary number

Answer 5

31

Question 6

Convert the binary number 10000001 to a denary number

Answer 6

129

Question 7

Convert the denary number 42 to an 8-bit binary number

Answer 7

00101110

Question 8

Convert the denary number 100to an 8-bit binary number

Answer 8

01100100

Question 9

Convert the denary number 74 to an 8-bit binary number

Answer 9

01001100

Question 10

How many digits does the hexadecimal number system use? What are they?

Answer 10

16 (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F,)

Question 11

Why are there letters in this system?

Answer 11

So it can be base 16

Question 12

What is the hex value for the number 12?

Answer 12

C

Question 13

What is the hex value for the number 7?

Answer 13

7

Question 14

Convert the binary number 00110111 to a hexadecimal number

Answer 14

37

Question 15

What is the purpose of using the hexadecimal number system?

Answer 15

To represent larger numbers with less characters

Question 16

Describe what an image pixel is.

Answer 16

A pixel is the smallest unit of a digital image or graphic that can be displayed.

Question 17

What is meant by the term colour depth?

Answer 17

Colour depth, also known as bit depth, is either the number of bits used to indicate the colour of a single pixel, or the number of bits used for each colour component of a single pixel.

Question 18

What are the 3 colours used in image pixels?

Answer 18

Red, Green and Blue

Question 19

An image has a colour depth of 4. How many different colours are available for this image?

Answer 19

16

Question 20

What is the purpose of the ASCII character set?

Answer 20

ASCII , an acronym for American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices.

Question 21

How many characters are represented by the ASCII character set?

Answer 21

128 characters

Question 22

What is the need for the Unicode character set?

Answer 22

Unicode is a standard with the goal to cover all possible characters in the world (can hold up to 1,114,112 characters, meaning 21 bits/character maximum.

Question 23

What is Abstraction?

Answer 23

Abstraction in computer science is the process of simplifying complex systems by focusing on essential details while ignoring unnecessary complexities.

Question 24

What is Decomposition?

Answer 24

In computer science, decomposition is a problem-solving technique that involves breaking down complex problems into smaller, more manageable parts.

Question 25

What is Pattern recognition?

Answer 25

Pattern recognition is a field in computer science that focuses on identifying patterns and regularities in data using machine learning algorithms.

Question 26

( Start ) ( End )

Answer 26

Terminator Start/end It shows where the start and end of the algorithm is.

Question 27

Fries? ( yes or no )

Answer 27

Decision This is used to check a condition. It can only have 2 outputs (yes/no). It cannot have 1 output.

Question 28

[ Order Burger ]

Answer 28

Process This is an action that needs to happen

Question 29

[Input] {" which object