ISecondary - Topic 3

Data representation

ASCII

The ASCII character set is a 7-bit set of codes that allows 128 different characters.

That is enough for every upper-case letter, lower-case letter, digit and punctuation mark on most keyboards.

ASCII is only used for the English language.

Unicode

Unicode uses between 8 and 32 bits per character,

so it can represent characters from languages from all around the world.

ASCII vs Unicode

Multiple Choice

Colour depth refers to:

• How many bits are used in a file to store colour information in every pixel
• Resolution divided by the number of colours in an image.
• Degree of file compression applied to an image file.
• Repeated resampling of an image.

Multiple Choice

Quality of an image depends on:

• Resolution
• Metadata
• Screen size
• Computer's speed

Multiple Choice

The higher the resolution, the ____ the file size.

• Smaller
• Larger

Multiple Choice

Each pixel is displayed using a combination of what three colours?

• Blue, green and purple
• Red, grey and white
• Red, green and blue
• White, red and blue

Multiple Choice

The higher the number of pixels, the _________________ the image quality

• Worse

• Smaller

• Better

• None of the above

Multiple Choice

The number of pixels displayed on screen is known as ________________

• Viewing Size

• Colour Depth

• Resolution

Multiple Choice

What are the basic colours that make up a pixel?

You may choose more than one answer

• Red, Orange, Yellow

• Red, Blue, Green

• Yellow, Orange, Purple

• Red, Blue, Purple

Multiple Choice

Increasing the colour depth means…

• A bigger range of colours can be used for each pixel

• More pixels are in the image.

• More colours are in the image.

• Darker colours

Multiple Choice

Which of these character sets allows the largest number of different characters?

• ASCII

• Extended ASCII

• Unicode

Multiple Choice

Upper and lower case letters have a different ASCII code.

• True

• False

Multiple Choice

The (standard) ASCII code is capable of representing non-European languages.

• True
• False

Multiple Choice

How many bits are used in (standard) ASCII?

• 16
• 1
• 7
• 8

Open Ended

Convert 4000MB to GB

Open Ended

Convert 4MB to KB

Open Ended

Convert 4TB to MB

Multiple Choice

A character set is...

• What language can be used in a computer system.
• The fonts that a computer has installed.
• The possible characters that can be represented by a computer system.

Multiple Choice

ASCII can represent an emoji

• True

• False

Multiple Choice

Convert 0001011 into denary.

• 8

• 11

• 10

• 15

Multiple Choice

10₂ can be read as what decimal number?

• 10

• 1

• 4

• 2

Multiple Choice

Convert this to a decimal number

• 13
• 12
• 10
• 8

Multiple Choice

Why was Unicode developed in 1991?

• To improve the character sets on computers
• Needed so we could display non-printing characters
• There was a need for a universal standard and more characters to cover all languages on earth.
• To replace early character sets used on teletype and teleprinting machines

Multiple Choice

How many bits are used in ASCII?

• 7
• 8
• 9
• 16

Multiple Choice

ASCII stands for what?

• Armenia Standard Code Information Interchange
• Angola Standard Code Information Interchange
• American Standard Code Information Interchange
• American Super Code Information Interchange

Multiple Choice

The following is a correct order of units of storage from lowest to highest:

• a bit, a byte, a kilobyte, a megabyte, a gigabyte, a terabyte

• a bit, a byte, a kilobyte, a terabyte, a megabyte, a gigabyte,

• a byte, a bit, a megabyte, a kilobyte, a gigabyte, a terabyte

• a byte, a bit, a megabyte, a kilobyte, a gigabyte, a terabyte

Multiple Choice

Binary is a base ______ number system

• 2

• 10

• 16

• 45

Multiple Choice

What is the largest number you can represent with 8 bits?

• 64
• 128
• 200
• 255

Multiple Choice

A bitmap image is made up of

• Pixels
• Colours
• Sounds
• Samples
• Characters

Multiple Choice

A byte is

• 8 bits
• 4 bits