Computer Hardware MCQ – Microprocessor

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Here’s a set of 25 multiple-choice questions (MCQs) on Microprocessors covering fundamental concepts, architecture, instruction sets, and applications.

Microprocessor MCQ

  1. What is a microprocessor?
    a) A multipurpose, programmable clock-driven electronic device
    b) A memory storage device
    c) An input/output controller
    d) A power supply regulator
    Answer: a
  2. Who invented the first microprocessor?
    a) Intel
    b) AMD
    c) IBM
    d) Motorola
    Answer: a (Intel 4004 in 1971)
  3. The first microprocessor was:
    a) 8-bit
    b) 4-bit
    c) 16-bit
    d) 32-bit
    Answer: b (Intel 4004 – 4-bit)
  4. The ALU in a microprocessor performs:
    a) Logical operations only
    b) Arithmetic operations only
    c) Both arithmetic and logical operations
    d) Data storage
    Answer: c
  5. The control unit in a microprocessor is responsible for:
    a) Data processing
    b) Controlling instruction flow
    c) Storing data
    d) Power management
    Answer: b
  6. Which of the following is not a part of a microprocessor?
    a) ALU
    b) CU
    c) RAM
    d) Registers
    Answer: c (RAM is external memory)
  7. The program counter (PC) holds:
    a) Data to be processed
    b) Address of the next instruction
    c) Results of arithmetic operations
    d) Stack memory address
    Answer: b
  8. Which register stores intermediate results in the CPU?
    a) Accumulator
    b) Instruction Register
    c) Stack Pointer
    d) Program Counter
    Answer: a
  9. The bus used to transfer data between CPU and memory is:
    a) Address bus
    b) Data bus
    c) Control bus
    d) System bus
    Answer: b
  10. The width of the address bus determines:
    a) Data transfer speed
    b) Maximum addressable memory
    c) Clock speed
    d) Number of I/O ports
    Answer: b
  11. Which of the following is a 1-byte instruction in 8085?
    a) LXI H, 2050H
    b) MOV A, B
    c) JMP 3000H
    d) CALL 2500H
    Answer: b
  12. The RST 7.5 interrupt in 8085 is a:
    a) Software interrupt
    b) Maskable interrupt
    c) Non-maskable interrupt
    d) DMA request
    Answer: b
  13. Which instruction does not affect flags in 8085?
    a) ADD B
    b) INR A
    c) CMP B
    d) MOV A, B
    Answer: d
  14. PUSH B in 8085 affects:
    a) Stack Pointer (decrements by 2)
    b) Stack Pointer (increments by 2)
    c) Program Counter
    d) Accumulator
    Answer: a
  15. The SIM instruction in 8085 is used for:
    a) Interrupt masking
    b) Serial data transmission
    c) Both a and b
    d) None of the above
    Answer: c
  16. EPROM stands for:
    a) Erasable Programmable ROM
    b) Electrically Programmable ROM
    c) Embedded Program ROM
    d) Extended Program ROM
    Answer: a
  17. Which memory is volatile?
    a) ROM
    b) RAM
    c) EPROM
    d) EEPROM
    Answer: b
  18. Memory-mapped I/O uses:
    a) Separate address space for I/O
    b) Same address space as memory
    c) Only control bus
    d) None of the above
    Answer: b
  19. DMA stands for:
    a) Direct Memory Access
    b) Dynamic Memory Allocation
    c) Data Memory Access
    d) Digital Memory Address
    Answer: a
  20. Cache memory is used to:
    a) Store backup data
    b) Speed up CPU-memory access
    c) Increase RAM capacity
    d) Replace ROM
    Answer: b
  21. The 8086 microprocessor is a:
    a) 8-bit processor
    b) 16-bit processor
    c) 32-bit processor
    d) 64-bit processor
    Answer: b
  22. Which register in 8086 is used for string operations?
    a) AX
    b) BX
    c) SI
    d) SP
    Answer: c (Source Index)
  23. The 80386 is a:
    a) 8-bit processor
    b) 16-bit processor
    c) 32-bit processor
    d) 64-bit processor
    Answer: c
  24. Pipelining improves:
    a) Clock speed
    b) Instruction throughput
    c) Memory size
    d) Power consumption
    Answer: b
  25. RISC stands for:
    a) Reduced Instruction Set Computer
    b) Random Instruction Set Computing
    c) Regulated Instruction System Computer
    d) None of the above
    Answer: a