Unit 1 Computer Organization Session 2 Components of Computer
Self Assessement Exercise
1. Explain storage devices of a computer.
Answer:
Storage devices are core hardware components used to store data, instructions, and programs either temporarily or permanently. They enable the computer to hold the operating system and running programs in immediate memory (such as RAM), as well as store files, software, and persistent user data long-term (such as Hard Disks, Pen Drives, and CDs/DVDs).
2. Describe secondary and primary storage devices of a computer.
Answer:
- Primary Storage (Main Memory): Devices like RAM (Random Access Memory) store data and program instructions currently being executed by the CPU. Whenever the computer starts up, the operating system is loaded into RAM. It provides high-speed access to active tasks, but data must first be fetched from secondary storage into RAM before execution.
- Secondary Storage (Auxiliary Storage): Non-volatile devices like Hard Disks, Pen Drives/Flash Drives, and Optical Discs are used for permanent, long-term storage of user files, programs, and data. Programs are permanently stored here and transferred to RAM when needed, then saved back to secondary storage upon completion.
3. Write a short note on Optical storage devices.
Answer: Optical storage devices use optical technology (lasers) to read and write data. Common examples include Compact Discs (CDs) and Digital Video Discs (DVDs).
- Data stored on a CD or DVD is accessed by inserting the disc into a specialized Disc Drive.
- The storage capacity of a DVD is significantly higher than that of a CD.
4. Explain the role of Power Supply Unit.
Answer: The Power Supply Unit (PSU) converts the alternating current (AC) power supply received from wall outlets (homes or offices) into the low-voltage direct current (DC) required to run the internal electronic components of the computer.
5. Explain various units to measure storage capacity of a device. Give the smallest unit.
Answer: Every bit of information in a computer is stored in terms of binary digits (0s and 1s)[cite: 1]. The standard hierarchy of units used to measure memory and storage capacity is as follows[cite: 1]:
- Bit: The smallest, fundamental unit representing a single binary digit (0 or 1)[cite: 1].
- 1 Nibble = 4 bits[cite: 1]
- 1 Byte (B) = 8 bits[cite: 1]
- 1 Kilobyte (KB) = 1024 Bytes[cite: 1]
- 1 Megabyte (MB) = 1024 KB[cite: 1]
- 1 Gigabyte (GB) = 1024 MB[cite: 1]
- 1 Terabyte (TB) = 1024 GB[cite: 1]
- 1 Petabyte (PB) = 1024 TB[cite: 1]
- 1 Exabyte (EB) = 1024 PB[cite: 1]
- 1 Zettabyte (ZB) = 1024 EB[cite: 1]
- 1 Yottabyte (YB) = 1024 ZB[cite: 1]
The smallest unit of computer storage is the Bit[cite: 1].
6: Do the following conversions:
a. 2 GB = ___________ KB
Answer: 2,097,152 KB (or 2 × 10242 KB)
Calculation:
1 GB = 1024 MB[cite: 1]
1 MB = 1024 KB[cite: 1]
2 GB = 2 × 1024 × 1024 KB = 2,097,152 KB
b. 210 MB (or 210 MB) = ___________ B
Answer:
- If interpreted as 210 MB:
1 MB = 1024 × 1024 Bytes = 210 × 210 Bytes = 220 Bytes[cite: 1]
210 MB = 210 × 220 Bytes = 230 Bytes (or 1,073,741,824 Bytes) - If interpreted literally as 210 MB:
210 MB = 210 × 1024 × 1024 Bytes = 220,200,960 Bytes[cite: 1]
By Anjeev Kr Singh – Computer Science Educator
Published on : September 2, 2026 | Updated on : September 2, 2026
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