Section A: Short-Answer Questions
CPU Components (2 marks):
Arithmetic logic unit (ALU), control unit, clock, register, bus. [1 mark for three components]
Role (e.g., ALU performs calculations and logic operations). [1 mark]
Explanation: The CPU components work together to process instructions; e.g., ALU handles math/logic.
Bus (1 mark):
A collection of wires that transmit data/signals between components. [1 mark]
Explanation: Buses enable communication within the CPU and with memory.
CPU Performance Factors (2 marks):
Clock speed, number of processor cores, cache size. [1 mark each for any two]
Explanation: These factors determine how quickly and efficiently the CPU processes data.
Fetch Stage (1 mark):
The next instruction is fetched from main memory to the CPU. [1 mark]
Explanation: This is the first step in executing instructions.
RAM vs ROM (2 marks):
RAM is volatile (loses data when powered off), ROM is non-volatile (retains data). [1 mark]
RAM is read/write, ROM is read-only. [1 mark]
Explanation: RAM holds temporary data/programs; ROM holds permanent firmware.
Secondary Storage Reason (1 mark):
To store data persistently when the computer is off (non-volatile). [1 mark]
Explanation: Unlike main memory, it retains data without power.
Embedded System (1 mark):
A dedicated computer system within a larger device. Example: Microwave controller. [1 mark]
Explanation: Embedded systems perform specific tasks, unlike general-purpose non-embedded systems (e.g., PC).
Section B: Explanation Questions
ALU and Control Unit (3 marks):
ALU: Performs arithmetic (e.g., addition) and logic operations (e.g., comparisons). [1.5 marks]
Control Unit: Coordinates CPU operations, directs data flow, and decodes instructions. [1.5 marks]
Explanation: ALU handles computations; control unit manages the process.
Cache Size Effect (2 marks):
Larger cache stores more frequently used data closer to CPU, reducing fetch time from main memory. [1 mark]
Improves performance by speeding up access. [1 mark]
Explanation: Cache is faster than RAM, so bigger cache means fewer slow memory accesses.
Fetch-Execute Cycle (3 marks):
Fetch: Instruction fetched from main memory to CPU. [1 mark]
Decode: Instruction interpreted to determine actions. [1 mark]
Execute: Instruction carried out, may involve memory read/write. [1 mark]
Explanation: The cycle repeats continuously for program execution.
Main Memory vs Secondary Storage (3 marks):
Main memory (e.g., RAM) is volatile, fast, directly accessible by CPU. [1 mark]
Secondary storage is non-volatile, slower, not directly CPU-accessible. [1 mark]
Volatile loses data on power off; non-volatile retains it. [1 mark]
Explanation: Main memory for running programs; secondary for long-term storage.
Solid State vs Magnetic (2 marks):
Solid state (SSD): Uses electrical circuits (e.g., NAND) for storage; advantage: fast/durable; disadvantage: expensive. [1 mark]
Magnetic (HDD): Uses magnetic fields on spinning disks; advantage: high capacity/cheap; disadvantage: slower/moving parts fail. [1 mark]
Explanation: Solid state is electronic; magnetic is mechanical.
Cloud Storage (2 marks):
Remote storage using magnetic/solid state at a distant location. [1 mark]
Advantage: Accessible anywhere, scalable; disadvantage: Requires internet, security risks. [1 mark, 0.5 each]
Explanation: Vs local: Cloud offers convenience but depends on connectivity.
Total Marks: 25