Computer Architecture Exam
Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. Which component of a computer is primarily responsible for
executing instructions and performing arithmetic and logical
operations?
A. Main memory
B. Central Processing Unit (CPU)
C. Secondary storage
D. Input/output controller
Answer: B. Central Processing Unit (CPU)
Rationale: The CPU executes program instructions and performs
arithmetic, logical, control, and data-processing operations. It
contains major components such as the arithmetic logic unit, control
unit, and registers.
2. Which CPU component performs arithmetic and logical
operations?
A. Control unit
B. Cache controller
C. Arithmetic Logic Unit (ALU)
D. Program counter
Answer: C. Arithmetic Logic Unit (ALU)
,Rationale: The ALU performs operations such as addition, subtraction,
comparison, AND, OR, XOR, and other logical or arithmetic functions
required by instructions.
3. What is the primary function of the control unit?
A. Store permanent files
B. Perform floating-point multiplication only
C. Coordinate and control instruction execution
D. Increase hard-drive capacity
Answer: C. Coordinate and control instruction execution
Rationale: The control unit interprets instructions and generates
control signals that coordinate the activities of the ALU, registers,
memory, and input/output components.
4. Which register normally contains the address of the next
instruction to be executed?
A. Instruction register
B. Memory address register
C. Program counter
D. Accumulator
Answer: C. Program counter
Rationale: The program counter, also called the instruction pointer in
many architectures, stores the address of the next instruction that the
processor should fetch.
5. Which register stores the instruction currently being decoded or
executed?
A. Program counter
B. Instruction register
,C. Stack pointer
D. Status register
Answer: B. Instruction register
Rationale: The instruction register temporarily holds the instruction
fetched from memory so that the control unit can decode it and
coordinate its execution.
6. What is the purpose of CPU registers?
A. Provide long-term file storage
B. Replace all forms of main memory
C. Provide very fast storage for operands, addresses, instructions,
and intermediate results
D. Control network traffic
Answer: C. Provide very fast storage for operands, addresses,
instructions, and intermediate results
Rationale: Registers are located inside or very close to the processor
and provide extremely fast storage needed during instruction
execution.
7. Which memory is generally fastest among the following?
A. Hard disk
B. Main memory
C. SSD
D. CPU register
Answer: D. CPU register
Rationale: CPU registers are designed for extremely fast access by the
processor and are generally faster than cache, RAM, and secondary
storage.
, 8. What does the term "instruction cycle" describe?
A. The process of formatting a disk
B. The sequence of operations used to fetch, decode, and execute an
instruction
C. The lifetime of a computer
D. The process of installing an operating system
Answer: B. The sequence of operations used to fetch, decode, and
execute an instruction
Rationale: An instruction cycle commonly includes instruction fetch,
decoding, operand access, execution, and sometimes memory access
and write-back stages.
9. Which operation normally occurs first in the instruction cycle?
A. Write-back
B. Decode
C. Execute
D. Fetch
Answer: D. Fetch
Rationale: During the fetch stage, the processor obtains the next
instruction from memory using the address contained in the program
counter.
10. What is instruction decoding?
A. Converting binary files into text
B. Determining the operation and operands represented by an
instruction
C. Moving files from RAM to disk
D. Compressing machine code
Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. Which component of a computer is primarily responsible for
executing instructions and performing arithmetic and logical
operations?
A. Main memory
B. Central Processing Unit (CPU)
C. Secondary storage
D. Input/output controller
Answer: B. Central Processing Unit (CPU)
Rationale: The CPU executes program instructions and performs
arithmetic, logical, control, and data-processing operations. It
contains major components such as the arithmetic logic unit, control
unit, and registers.
2. Which CPU component performs arithmetic and logical
operations?
A. Control unit
B. Cache controller
C. Arithmetic Logic Unit (ALU)
D. Program counter
Answer: C. Arithmetic Logic Unit (ALU)
,Rationale: The ALU performs operations such as addition, subtraction,
comparison, AND, OR, XOR, and other logical or arithmetic functions
required by instructions.
3. What is the primary function of the control unit?
A. Store permanent files
B. Perform floating-point multiplication only
C. Coordinate and control instruction execution
D. Increase hard-drive capacity
Answer: C. Coordinate and control instruction execution
Rationale: The control unit interprets instructions and generates
control signals that coordinate the activities of the ALU, registers,
memory, and input/output components.
4. Which register normally contains the address of the next
instruction to be executed?
A. Instruction register
B. Memory address register
C. Program counter
D. Accumulator
Answer: C. Program counter
Rationale: The program counter, also called the instruction pointer in
many architectures, stores the address of the next instruction that the
processor should fetch.
5. Which register stores the instruction currently being decoded or
executed?
A. Program counter
B. Instruction register
,C. Stack pointer
D. Status register
Answer: B. Instruction register
Rationale: The instruction register temporarily holds the instruction
fetched from memory so that the control unit can decode it and
coordinate its execution.
6. What is the purpose of CPU registers?
A. Provide long-term file storage
B. Replace all forms of main memory
C. Provide very fast storage for operands, addresses, instructions,
and intermediate results
D. Control network traffic
Answer: C. Provide very fast storage for operands, addresses,
instructions, and intermediate results
Rationale: Registers are located inside or very close to the processor
and provide extremely fast storage needed during instruction
execution.
7. Which memory is generally fastest among the following?
A. Hard disk
B. Main memory
C. SSD
D. CPU register
Answer: D. CPU register
Rationale: CPU registers are designed for extremely fast access by the
processor and are generally faster than cache, RAM, and secondary
storage.
, 8. What does the term "instruction cycle" describe?
A. The process of formatting a disk
B. The sequence of operations used to fetch, decode, and execute an
instruction
C. The lifetime of a computer
D. The process of installing an operating system
Answer: B. The sequence of operations used to fetch, decode, and
execute an instruction
Rationale: An instruction cycle commonly includes instruction fetch,
decoding, operand access, execution, and sometimes memory access
and write-back stages.
9. Which operation normally occurs first in the instruction cycle?
A. Write-back
B. Decode
C. Execute
D. Fetch
Answer: D. Fetch
Rationale: During the fetch stage, the processor obtains the next
instruction from memory using the address contained in the program
counter.
10. What is instruction decoding?
A. Converting binary files into text
B. Determining the operation and operands represented by an
instruction
C. Moving files from RAM to disk
D. Compressing machine code
