Computer Organisation MCQ Test

1. Which number system uses only the digits 0 and 1?

• A. Decimal
• B. Binary
• C. Octal
• D. Hexadecimal

Answer: Binary

2. What is the base of the octal number system?

• A. 2
• B. 8
• C. 10
• D. 16

Answer: 8

3. What is the base of the hexadecimal number system?

• A. 8
• B. 10
• C. 16
• D. 32

Answer: 16

4. Which digits and letters are used in hexadecimal?

• A. 0-9 only
• B. 0-9 and A-F
• C. 0-7 only
• D. A-Z only

Answer: 0-9 and A-F

5. What is the decimal value of the binary number 1010?

• A. 8
• B. 10
• C. 12
• D. 20

Answer: 10

6. What is the decimal value of the binary number 1111?

• A. 14
• B. 15
• C. 16
• D. 31

Answer: 15

7. What is the binary equivalent of the decimal number 8?

• A. 100
• B. 1000
• C. 1010
• D. 1100

Answer: 1000

8. What is the hexadecimal equivalent of the decimal number 255?

• A. FE
• B. FF
• C. F0
• D. 100

Answer: FF

9. How many bits make up one byte?

• A. 4
• B. 8
• C. 16
• D. 32

Answer: 8

10. How many bits are in a nibble?

• A. 2
• B. 4
• C. 8
• D. 16

Answer: 4

11. How many bytes are in one kilobyte (binary definition)?

• A. 1000
• B. 1024
• C. 512
• D. 2048

Answer: 1024

12. Which is the largest unit among these?

• A. Megabyte
• B. Gigabyte
• C. Terabyte
• D. Kilobyte

Answer: Terabyte

13. What does ASCII stand for?

• A. American Standard Code for Information Interchange
• B. Advanced System Character Input Interface
• C. Automatic Serial Code for Internal Instructions
• D. American System Computer Interface Index

Answer: American Standard Code for Information Interchange

14. How many characters can standard 7-bit ASCII represent?

• A. 64
• B. 128
• C. 256
• D. 512

Answer: 128

15. Which encoding standard supports characters from most world languages?

• A. ASCII
• B. Unicode
• C. EBCDIC
• D. BCD

Answer: Unicode

16. What does the AND gate output when both inputs are 1?

• A. 0
• B. 1
• C. Undefined
• D. It depends

Answer: 1

17. What does the OR gate output when both inputs are 0?

• A. 1
• B. 0
• C. Undefined
• D. Both

Answer: 0

18. What does a NOT gate do?

• A. Adds two inputs
• B. Inverts the input
• C. Multiplies inputs
• D. Stores a value

Answer: Inverts the input

19. Which gate outputs 1 only when its inputs differ?

• A. AND
• B. OR
• C. XOR
• D. NAND

Answer: XOR

20. Which gates are called universal gates?

• A. AND and OR
• B. NAND and NOR
• C. XOR and XNOR
• D. NOT and AND

Answer: NAND and NOR

21. Why are NAND and NOR called universal gates?

• A. They are the fastest
• B. Any other logic gate can be built from them
• C. They use the least power
• D. They were invented first

Answer: Any other logic gate can be built from them

22. What is a half adder used for?

• A. Adding two bits producing a sum and a carry
• B. Adding three bits
• C. Subtracting bits
• D. Storing a bit

Answer: Adding two bits producing a sum and a carry

23. What can a full adder do that a half adder cannot?

• A. Produce a sum
• B. Accept a carry input
• C. Work with binary
• D. Produce a carry output

Answer: Accept a carry input

24. What is a flip-flop in digital electronics?

• A. A logic gate
• B. A circuit that stores one bit of data
• C. An arithmetic unit
• D. A bus

Answer: A circuit that stores one bit of data

25. What does CPU stand for?

• A. Central Processing Unit
• B. Computer Power Unit
• C. Control Program Utility
• D. Central Program Unit

Answer: Central Processing Unit

26. Which two main units make up the CPU?

• A. RAM and ROM
• B. ALU and Control Unit
• C. Cache and Bus
• D. Input and Output

Answer: ALU and Control Unit

27. What does the ALU do?

• A. Stores data permanently
• B. Performs arithmetic and logical operations
• C. Controls the printer
• D. Manages the network

Answer: Performs arithmetic and logical operations

28. What does the Control Unit do?

• A. Performs calculations
• B. Directs the operation of the processor by decoding instructions
• C. Stores results
• D. Displays output

Answer: Directs the operation of the processor by decoding instructions

29. What is a register in a CPU?

• A. A large storage drive
• B. A small, very fast storage location inside the processor
• C. An input device
• D. A cooling component

Answer: A small, very fast storage location inside the processor

30. Which register holds the address of the next instruction to be executed?

• A. Accumulator
• B. Program Counter
• C. Instruction Register
• D. Stack Pointer

Answer: Program Counter

31. Which register holds the instruction currently being executed?

• A. Program Counter
• B. Instruction Register
• C. Accumulator
• D. Index Register

Answer: Instruction Register

32. Which register stores intermediate arithmetic results?

• A. Program Counter
• B. Accumulator
• C. Instruction Register
• D. Memory Address Register

Answer: Accumulator

33. What are the three main steps of the instruction cycle?

• A. Read, write, delete
• B. Fetch, decode, execute
• C. Input, process, output
• D. Load, store, jump

Answer: Fetch, decode, execute

34. What is a bus in computer architecture?

• A. A cooling fan
• B. A set of wires that carries data between components
• C. A storage device
• D. A power supply

Answer: A set of wires that carries data between components

35. Which bus carries the location of data in memory?

• A. Data bus
• B. Address bus
• C. Control bus
• D. System bus

Answer: Address bus

36. Which bus carries the actual information being transferred?

• A. Address bus
• B. Data bus
• C. Control bus
• D. Expansion bus

Answer: Data bus

37. Which memory type loses its contents when power is switched off?

• A. ROM
• B. RAM
• C. Flash
• D. Hard disk

Answer: RAM

38. Which memory type retains its contents without power?

• A. RAM
• B. ROM
• C. Cache
• D. Register

Answer: ROM

39. Which memory is the fastest?

• A. Hard disk
• B. RAM
• C. Cache
• D. Registers

Answer: Registers

40. What is cache memory used for?

• A. Permanent storage
• B. Holding frequently used data close to the CPU for faster access
• C. Storing the operating system
• D. Backing up files

Answer: Holding frequently used data close to the CPU for faster access

41. Which cache level is normally fastest and smallest?

• A. L1
• B. L2
• C. L3
• D. L4

Answer: L1

42. What is the difference between SRAM and DRAM?

• A. SRAM is slower
• B. SRAM is faster and does not need refreshing; DRAM must be refreshed
• C. DRAM is used in registers
• D. There is no difference

Answer: SRAM is faster and does not need refreshing; DRAM must be refreshed

43. Which type of RAM is normally used for main system memory?

• A. SRAM
• B. DRAM
• C. PROM
• D. EPROM

Answer: DRAM

44. What is EPROM?

• A. Memory that cannot be changed
• B. Erasable Programmable ROM, erased with ultraviolet light
• C. A type of RAM
• D. A hard disk format

Answer: Erasable Programmable ROM, erased with ultraviolet light

45. Which storage device has no moving parts?

• A. Hard disk drive
• B. Solid state drive
• C. Floppy disk
• D. Optical drive

Answer: Solid state drive

46. What does the term 'word size' mean for a processor?

• A. The number of characters it can display
• B. The number of bits it processes at one time
• C. The size of its cache
• D. The clock speed

Answer: The number of bits it processes at one time

47. What does clock speed measure?

• A. The amount of memory
• B. How many cycles the processor performs per second
• C. The storage capacity
• D. The screen refresh rate

Answer: How many cycles the processor performs per second

48. In which unit is processor clock speed usually measured?

• A. Bytes
• B. Gigahertz
• C. Watts
• D. Pixels

Answer: Gigahertz

49. What is pipelining in a processor?

• A. Cooling the CPU with liquid
• B. Overlapping the stages of multiple instructions to increase throughput
• C. Connecting two processors
• D. Storing data in a queue

Answer: Overlapping the stages of multiple instructions to increase throughput

50. What does RISC stand for?

• A. Reduced Instruction Set Computer
• B. Random Internal Storage Chip
• C. Rapid Instruction Sequence Control
• D. Registered Integrated System Core

Answer: Reduced Instruction Set Computer

51. What is the main characteristic of a RISC processor?

• A. A large complex instruction set
• B. A small set of simple, fast instructions
• C. No registers
• D. No pipelining

Answer: A small set of simple, fast instructions

52. What is DMA in computer architecture?

• A. Direct Memory Access — devices transfer data without CPU involvement
• B. Dynamic Memory Allocation
• C. Digital Media Adapter
• D. Disk Management Area

Answer: Direct Memory Access — devices transfer data without CPU involvement

53. Which generation of computers used vacuum tubes?

• A. First
• B. Second
• C. Third
• D. Fourth

Answer: First

54. Which generation of computers introduced microprocessors?

• A. First
• B. Second
• C. Third
• D. Fourth

Answer: Fourth

55. Which architecture stores program instructions and data in the same memory?

• A. Harvard architecture
• B. Von Neumann architecture
• C. RISC architecture
• D. Parallel architecture

Answer: Von Neumann architecture

56. What is the two's complement used for?

• A. Storing decimals
• B. Representing negative numbers in binary
• C. Encoding text
• D. Compressing data

Answer: Representing negative numbers in binary

57. What is parity checking used for?

• A. Speeding up transfers
• B. Detecting single-bit errors in transmitted data
• C. Encrypting data
• D. Compressing data

Answer: Detecting single-bit errors in transmitted data