PRINCIPLES OF COMPUTER SCIENCE PAPER 1
2026 PRACTICE TEST QUESTIONS WITH
EXEMPLAR ANSWERS
◉ What are the key parts of a CPU? Answer: The key parts of a CPU
include the Arithmetic Logic Unit (ALU), Control Unit (CU), registers,
and cache memory.
◉ How does the CPU execute instructions? Answer: The CPU
executes instructions from programs stored in memory.
◉ What factors affect CPU performance? Answer: CPU performance
is affected by clock speed, number of cores, and cache size.
◉ What does the Control Unit (CU) do in a CPU? Answer: The
Control Unit (CU) directs the operation of the processor and
coordinates the activities of the other components.
◉ What operations does the ALU perform? Answer: Mathematical
and logical operations.
◉ What are the mathematical operations performed by the ALU?
Answer: Addition, subtraction, multiplication, and division.
,◉ What types of logical operations does the ALU handle? Answer:
Comparisons such as greater than, less than, or equal to.
◉ Why are logical operations important in programming? Answer:
They are crucial for decision making in programs.
◉ What does the ALU do when the CPU executes instructions
requiring calculations? Answer: The ALU processes the data and
returns the result to the CPU.
◉ What is the primary role of the Control Unit (CU) in a CPU?
Answer: To manage and coordinate the activities of the CPU.
◉ How does the Control Unit interact with memory? Answer: The
CU fetches instructions from memory.
◉ What does the Control Unit do after fetching instructions?
Answer: It decodes the instructions to determine the required
action.
◉ What signals does the Control Unit send? Answer: It sends signals
to other components to execute the instruction.
, ◉ What is ensured by the Control Unit in a computer system?
Answer: That each part of the computer works together correctly.
◉ Registers Answer: Very small, high-speed storage locations inside
the CPU used to temporarily hold data and instructions that are
currently being processed.
◉ Access Speed of Registers Answer: Registers can be accessed
much faster than RAM because they are located within the CPU.
◉ Program Counter (PC) Answer: Stores the address of the next
instruction to be executed.
◉ Memory Address Register (MAR) Answer: Used during memory
operations.
◉ Memory Data Register (MDR) Answer: Used during memory
operations.
◉ Cache Answer: A small amount of extremely fast memory located
close to or inside the CPU.
◉ Function of Cache Answer: Stores frequently used data and
instructions so the CPU can access them quickly.
2026 PRACTICE TEST QUESTIONS WITH
EXEMPLAR ANSWERS
◉ What are the key parts of a CPU? Answer: The key parts of a CPU
include the Arithmetic Logic Unit (ALU), Control Unit (CU), registers,
and cache memory.
◉ How does the CPU execute instructions? Answer: The CPU
executes instructions from programs stored in memory.
◉ What factors affect CPU performance? Answer: CPU performance
is affected by clock speed, number of cores, and cache size.
◉ What does the Control Unit (CU) do in a CPU? Answer: The
Control Unit (CU) directs the operation of the processor and
coordinates the activities of the other components.
◉ What operations does the ALU perform? Answer: Mathematical
and logical operations.
◉ What are the mathematical operations performed by the ALU?
Answer: Addition, subtraction, multiplication, and division.
,◉ What types of logical operations does the ALU handle? Answer:
Comparisons such as greater than, less than, or equal to.
◉ Why are logical operations important in programming? Answer:
They are crucial for decision making in programs.
◉ What does the ALU do when the CPU executes instructions
requiring calculations? Answer: The ALU processes the data and
returns the result to the CPU.
◉ What is the primary role of the Control Unit (CU) in a CPU?
Answer: To manage and coordinate the activities of the CPU.
◉ How does the Control Unit interact with memory? Answer: The
CU fetches instructions from memory.
◉ What does the Control Unit do after fetching instructions?
Answer: It decodes the instructions to determine the required
action.
◉ What signals does the Control Unit send? Answer: It sends signals
to other components to execute the instruction.
, ◉ What is ensured by the Control Unit in a computer system?
Answer: That each part of the computer works together correctly.
◉ Registers Answer: Very small, high-speed storage locations inside
the CPU used to temporarily hold data and instructions that are
currently being processed.
◉ Access Speed of Registers Answer: Registers can be accessed
much faster than RAM because they are located within the CPU.
◉ Program Counter (PC) Answer: Stores the address of the next
instruction to be executed.
◉ Memory Address Register (MAR) Answer: Used during memory
operations.
◉ Memory Data Register (MDR) Answer: Used during memory
operations.
◉ Cache Answer: A small amount of extremely fast memory located
close to or inside the CPU.
◉ Function of Cache Answer: Stores frequently used data and
instructions so the CPU can access them quickly.
