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Clock Throughput 0 / 20
Thermal Rank Heat Sink
1 [3 Marks]
Connect each part of the processor to its correct definition.
Control Unit (CU)
Cache
Arithmetic Logic Unit (ALU)
Performs mathematical calculations and logical operations.
Sends signals to direct the operations of the processor.
High speed memory inside the processor that stores recently used instructions.
✅ Mark Scheme
  • CU: Sends signals to direct operations...
  • Cache: High speed memory...
  • ALU: Performs mathematical calculations...
Score:
2 [3 Marks]
Click the correct box to identify which component each statement describes.
Statement ALU CU Cache
Sends control signals to components.
Stores frequently used instructions.
Performs subtraction.
✅ Mark Scheme
  • Row 1: CU
  • Row 2: Cache
  • Row 3: ALU
Score:
3 [4 Marks]
Describe two distinct functions of the Control Unit (CU).
💡 Hint: It manages the F-E cycle. It tells other parts what to do.
✅ Mark Scheme

Any two from:

  • Controls/coordinates the flow of data.
  • Sends signals to synchronize components.
  • Decodes instructions.
  • Runs the Fetch-Execute cycle.
⚠️ Examiner's Trap Do not just say "It controls the computer". This is too vague and gets 0 marks. You must mention data flow, signals, or decoding.
Score yourself (2 marks per function):
4 [4 Marks]
The ALU performs two types of operations. Identify them and give an example of each.
✅ Mark Scheme
  • Arithmetic: Addition (+), Subtraction (-), etc.
  • Logic: AND, OR, NOT, Comparisons (<, >, =).
Score yourself (Max 4):
5 [2 Marks]
Explain how cache size affects the performance of the CPU.
💡 Hint: Why is cache better than RAM? What happens if we have more of it?
✅ Mark Scheme
  • Cache stores frequently used instructions/data. (1)
  • These can be accessed faster than fetching from RAM. (1)
⚠️ Examiner's Trap Don't just say "It makes the computer faster". You must explain how (by reducing access time to RAM).
Score:
6 [2 Marks]
Computer A: 1 GHz, 2 MB Cache.
Computer B: 1 GHz, 512 KB Cache.

(a) Which is faster?
(b) Explain why.
✅ Mark Scheme

(a) Computer A

(b) Reason:

  • It has more cache (2MB > 512KB).
  • It can store more frequently used instructions for fast access.
Score (1 for choice, 1 for reason):
7 [2 Marks]
A student claims: "The Cache is just extra RAM, so it does exactly the same job."
Explain why the student is incorrect.
✅ Mark Scheme
  • Cache is faster than RAM.
  • Cache is closer to the CPU (or inside it).
  • Cache stores frequently used data, RAM stores currently running programs.
Score: