Unit 2 Computer Systems - Data Representation

Question 1

What is binary data?

Answer 1

Binary data is the system of representing information using only two states: on (1) and off (0), which is used in digital systems like computers.

Question 2

Why do computers use binary?

Answer 2

1. Simplicity – Transistors can only be on or off.
2. Storage – Binary can be stored in magnetic charges, DVDs, or punched cards.
3. Signal degradation resistance – Voltage drops don’t affect binary representation.

Question 3

What is the denary (decimal) number system?

Answer 3

A number system using base 10, where place values increase by powers of 10.

Question 4

How does the binary number system work?

Answer 4

It uses base 2, where place values increase by powers of 2 (e.g., 1, 2, 4, 8, 16…).

Question 5

What is floating point representation?

Answer 5

A method of storing real numbers in computers using a mantissa and an exponent.

Question 6

What are the three key elements of floating point representation?

Answer 6

1. Mantissa – The significant digits of the number.
2. Base – The number system used (e.g., 2 for binary, 10 for decimal).
3. Exponent – The power to which the base is raised.

Question 7

What is ASCII?

Answer 7

ASCII (American Standard Code for Information Interchange) is a character encoding system using 7 or 8 bits per character.

Question 8

What is Unicode?

Answer 8

A character encoding system that uses 16 bits to support over 65,000 characters from multiple languages.

Question 9

What are the two main types of computer graphics?

Answer 9

1. Bitmap graphics – Stored as a grid of pixels.
2. Vector graphics – Stored as mathematical instructions defining shapes.

Question 10

What are vector graphics?

Answer 10

Graphics defined by objects such as rectangles, ellipses, and lines, each with attributes like position and color.

Question 11

What is resolution in bitmap graphics?

Answer 11

The number of pixels in an image, often measured in:
- Pixels (width × height) (e.g., 1920×1080)
- Megapixels (e.g., 12 MP for cameras)
- Dots per inch (dpi) (used in scanning and printing)

Question 12

What is bit depth in images?

Answer 12

The number of bits used per pixel, which determines the number of colors available:
- 1-bit = 2 colors (black and white)
- 2-bit = 4 colors
- 8-bit (GIFs) = 256 colors
- 24-bit (JPEGs, True Color) = 16.7 million colors

Question 13

Why do bitmap images use compression?

Answer 13

To reduce file size since high-resolution images require large amounts of data storage.