Central Processing Unit

Apologies for the confusion! Here are 50 multiple-choice questions with their solutions based on the content provided:

MCQs with Solutions:

1. Which of the following is NOT a peripheral device?
   
   a) Keyboard
   
   b) Monitor
   
   c) CPU
   
   d) Printer
   
   Answer: c) CPU

2. What does ASCII stand for?
   
   a) American Standard Code for Instructional Interface
   
   b) American Standard Code for Information Interchange
   
   c) Automatic System Code for Internal Interaction
   
   d) Advanced Standard Communication Interchange
   
   Answer: b) American Standard Code for Information Interchange

3. How many bits are used to represent ASCII characters?
   
   a) 8
   
   b) 7
   
   c) 6
   
   d) 5
   
   Answer: b) 7

4. What is a peripheral device directly controlled by the computer called?
   
   a) Online device
   
   b) Offline device
   
   c) Isolated device
   
   d) Standalone device
   
   Answer: a) Online device

5. Which of the following is an example of an input device?
   
   a) Printer
   
   b) Light pen
   
   c) CRT monitor
   
   d) Plotter
   
   Answer: b) Light pen

6. In memory-mapped I/O, memory and I/O addresses are:
   
   a) Separate
   
   b) Shared in the same address space
   
   c) Mapped to different buses
   
   d) Not used together
   
   Answer: b) Shared in the same address space

7. Which input device uses optical technology to read barcodes?
   
   a) Magnetic stripe reader
   
   b) Barcode reader
   
   c) Touch screen
   
   d) Mouse
   
   Answer: b) Barcode reader

8. Which type of interrupt assigns a unique priority to each device?
   
   a) Polling
   
   b) Daisy-chaining
   
   c) Parallel priority
   
   d) Serial priority
   
   Answer: c) Parallel priority

9. What is the term for transferring a large block of data between memory and I/O devices without involving the CPU?
   
   a) Programmed I/O
   
   b) Interrupt-driven I/O
   
   c) Direct Memory Access (DMA)
   
   d) Cycle stealing
   
   Answer: c) Direct Memory Access (DMA)

10. In which mode does the CPU continuously check the I/O device status to transfer data?
    
    a) DMA
    
    b) Interrupt-initiated I/O
    
    c) Programmed I/O
    
    d) Burst transfer
    
    Answer: c) Programmed I/O

11. Which of the following provides hard copy output?
    
    a) CRT monitor
    
    b) Laser printer
    
    c) Barcode reader
    
    d) Mouse
    
    Answer: b) Laser printer

12. Which input device reads magnetic stripes on cards?
    
    a) Optical mark reader
    
    b) Magnetic stripe reader
    
    c) Barcode reader
    
    d) Touch screen
    
    Answer: b) Magnetic stripe reader

13. What is the typical function of an input-output interface?
    
    a) Transfer data between CPU and memory
    
    b) Transfer data between CPU and external devices
    
    c) Store data in the CPU
    
    d) Execute programs
    
    Answer: b) Transfer data between CPU and external devices

14. Which method is used to handle asynchronous data transfer between CPU and peripheral devices?
    
    a) Programmed I/O
    
    b) Handshaking
    
    c) Burst mode
    
    d) Interrupt-driven I/O
    
    Answer: b) Handshaking

15. The I/O device that prints text and graphics on paper is a:
    
    a) Monitor
    
    b) Printer
    
    c) Plotter
    
    d) Light pen
    
    Answer: b) Printer

16. Which character encoding standard uses 7 bits for alphanumeric characters?
    
    a) Unicode
    
    b) ASCII
    
    c) EBCDIC
    
    d) UTF-8
    
    Answer: b) ASCII

17. In isolated I/O, which type of instructions are used for communication?
    
    a) Arithmetic
    
    b) Control
    
    c) Input and Output
    
    d) Memory management
    
    Answer: c) Input and Output

18. What type of I/O devices are used to store data?
    
    a) Output devices
    
    b) Input-output devices
    
    c) Input devices
    
    d) Storage devices
    
    Answer: d) Storage devices

19. Which of the following is used to transfer data between CPU and memory?
    
    a) Programmed I/O
    
    b) Memory-mapped I/O
    
    c) Direct Memory Access (DMA)
    
    d) Interrupt-driven I/O
    
    Answer: b) Memory-mapped I/O

20. In which type of interrupt handling system do devices have their own interrupt vectors?
    
    a) Daisy-chaining
    
    b) Polling
    
    c) Parallel priority
    
    d) Serial priority
    
    Answer: c) Parallel priority

21. Which technique allows DMA to transfer one word at a time and release the bus back to the CPU?
    
    a) Burst transfer
    
    b) Cycle stealing
    
    c) Interrupt-driven I/O
    
    d) Programmed I/O
    
    Answer: b) Cycle stealing

22. Which peripheral device is used to create digital signatures on documents?
    
    a) Mouse
    
    b) Printer
    
    c) Digitizer
    
    d) Scanner
    
    Answer: c) Digitizer

23. What is the purpose of a control command in an I/O interface?
    
    a) To activate the peripheral device
    
    b) To test the status of the device
    
    c) To read data from memory
    
    d) To write data to memory
    
    Answer: a) To activate the peripheral device

24. Which of the following stores alphanumeric information in binary code?
    
    a) EBCDIC
    
    b) ASCII
    
    c) UTF-16
    
    d) UTF-8
    
    Answer: b) ASCII

25. In a daisy-chain priority system, what happens if a device has the highest priority?
    
    a) It waits for other devices to finish
    
    b) It immediately processes the interrupt
    
    c) It passes the interrupt signal to the next device
    
    d) It ignores the interrupt signal
    
    Answer: b) It immediately processes the interrupt

26. What is the function of the word count register in DMA?
    
    a) To store the number of data words to be transferred
    
    b) To control the transfer rate
    
    c) To store the memory address of data
    
    d) To generate control signals
    
    Answer: a) To store the number of data words to be transferred

27. Which method involves the CPU sending an interrupt request to a specific device?
    
    a) Memory-mapped I/O
    
    b) Isolated I/O
    
    c) Interrupt-initiated I/O
    
    d) Programmed I/O
    
    Answer: c) Interrupt-initiated I/O

28. Which input-output method uses CPU as an intermediate path for data transfer?
    
    a) Direct Memory Access
    
    b) Interrupt-initiated I/O
    
    c) Programmed I/O
    
    d) Isolated I/O
    
    Answer: c) Programmed I/O

29. What is the main disadvantage of using polling for interrupt handling?
    
    a) It's fast
    
    b) It requires more hardware
    
    c) It can be slow and inefficient
    
    d) It’s hard to implement
    
    Answer: c) It can be slow and inefficient

30. Which type of device is a plotter?
    
    a) Input device
    
    b) Output device
    
    c) Input-output device
    
    d) Storage device
    
    Answer: b) Output device

31. In which mode does the CPU respond to the interrupt when it finishes its current instruction?
    
    a) Immediate response mode
    
    b) Asynchronous mode
    
    c) Synchronous mode
    
    d) Deferred response mode
    
    Answer: c) Synchronous mode

32. What does the status command do in an I/O interface?
    
    a) It tests various status conditions in the interface
    
    b) It transfers data from CPU to the peripheral
    
    c) It writes data to memory
    
    d) It reads data from memory
    
    Answer: a) It tests various status conditions in the interface

33. Which type of I/O device converts light signals into electronic signals?
    
    a) Printer
    
    b) Touch screen
    
    c) Light pen
    
    d) Mouse
    
    Answer: c) Light pen

34. What does DMA stand for?
    
    a) Direct Memory Application
    
    b) Direct Memory Access
    
    c) Device Memory Application
    
    d) Data Memory Access
    
    Answer: b) Direct Memory Access

35. Which device is used for hard copy output?
    
    a) Monitor
    
    b) Printer
    
    c) Touch screen
    
    d) Barcode reader
    
    Answer: b) Printer

36. In asynchronous data transfer, how do units communicate?
    
    a) By sharing the same clock