Module 2: IT System Architecture and Data Formats

Question 1

Name the primary components of a typical computer

Answer 1

CPU (Central Processing Unit): Executes instructions.

RAM (Random Access Memory): Temporary data storage for active tasks.

Storage (HDD/SSD): Long-term data storage.

Motherboard: Connects all components.

Power Supply Unit (PSU): Provides power to components.

GPU (Graphics Processing Unit): Renders images/video (dedicated or integrated).

Cooling System: Prevents overheating (fans, heatsinks, liquid cooling).

Input Devices: Keyboard, mouse, etc.

Output Devices: Monitor, speakers, etc.

Case (Chassis): Encloses and protects components.

Question 2

Describe the advantages of data compression.

Answer 2

Saves Storage Space: Reduces file size.

Faster Transmission: Speeds up data transfer.

Lower Bandwidth Use: Efficient for networks.

Cost-Efficient: Reduces storage and transfer costs.

Improved Performance: Faster loading and processing.

Question 3

Describe the disadvantages of data compression

Answer 3

Loss of Quality (Lossy) - Some data may be permanently removed.

Processing Time: Compression and decompression take time and CPU resources.

Compatibility Issues: Not all systems support all compression formats.

Corruption Risk: Compressed files are more prone to damage—small errors can make them unusable.

Limited Benefit for Some Files: Already compressed files (e.g. JPEG, MP4) may not reduce much in size.

Question 4

Describe ASCII, extended ASCII, Unicode, and UTF-8.

Answer 4

ASCII (American Standard Code for Information Interchange):
Uses 7 bits to represent 128 characters (letters, digits, symbols, control codes).

Extended ASCII:
Uses 8 bits to represent 256 characters, adding symbols and characters for European languages.

Unicode:
A universal standard encoding system supporting over 143,000 characters from all major writing systems.

UTF-8 (Unicode Transformation Format - 8-bit):
A variable-length Unicode encoding (1–4 bytes) that’s backward-compatible with ASCII.

Question 5

What are the advantages of Unicode over ASCII?

Answer 5

Supports Multiple Languages: Handles characters from all writing systems, not just English.

Universal Standard: Enables consistent text representation across platforms and devices.

Extensible: Can encode emojis, symbols, and historical scripts.

Backward-Compatible (UTF-8): Maintains compatibility with ASCII for older systems.

Question 6

Define Digitization and give an example

Answer 6

Definition:
The process of converting information into a digital (computer-readable) format.

Example:
Scanning a paper document to create a PDF file.

Question 7

Describe Lossy and Lossless Compression

Answer 7

Lossy Compression:
Reduces file size by permanently removing some data.
Example: JPEG, MP3.
Use: Images, audio, video.

Lossless Compression:
Reduces file size without losing any data, original can be restored.
Example: ZIP, PNG.
Use: Text, software, images needing full quality.

Question 8

Describe the advantage and disadvantages of Lossy Compression.

Answer 8

Advantages:

Much smaller file sizes

Faster to transfer and load

Ideal for media (audio, images, video)

Disadvantages:

Permanent loss of some data

Reduced quality (may be noticeable)

Not suitable for critical data (e.g., text, software)

Question 9

Describe the advantage and disadvantages of Lossless Compression.

Answer 9

Advantages:

No loss of data or quality

Original file can be perfectly restored

Suitable for important or sensitive data

Disadvantages:

Larger file sizes compared to lossy

Slower transfer and storage

Less effective for multimedia files

Question 10

Describe the five simple data types and give an example for each of them.

Answer 10

1. Integer
   Whole numbers without decimals.
   Example: 42
2. Float (Real)
   Numbers with decimal points.
   Example: 3.14
3. Character
   A single letter, digit, or symbol.
   Example: ‘A’
4. String
   A sequence of characters.
   Example: “Hello”
5. Boolean
   Represents true or false values.
   Example: True or False

Question 11

Describe Sampling method. When is it used and how is it conducted?

Answer 11

Definition:
The process of converting analog signals (like sound) into digital data by measuring the signal at regular intervals.

When Used:
In digital audio and video recording, to convert real-world signals into a digital format.

How Conducted:

Measure the amplitude of the analog signal at regular time intervals (samples).

Each sample is then stored as a binary value.

The sampling rate (e.g., 44.1 kHz) affects quality—higher rate = better quality.