1. . The main purpose of an I/O system is:
(A) Manage CPU scheduling
(B) Enable communication between CPU and I/O devices
(C) Manage memory
(D) Store files permanently
2. . A device controller is:
(A) Hardware that controls an I/O device
(B) Part of CPU
(C) File system module
(D) Memory unit
3. . Programmed I/O requires:
(A) DMA for transfer
(B) CPU to continue other tasks
(C) CPU to wait until I/O is complete
(D) Interrupts for signaling
4. . Interrupt-driven I/O allows:
(A) CPU to execute other instructions while waiting
(B) CPU to wait idle
(C) Only sequential access
(D) DMA transfer only
5. . Direct Memory Access (DMA) is used to:
(A) Increase CPU speed
(B) Transfer data without CPU intervention
(C) Store files
(D) Manage memory
6. . Spooling is used to:
(A) Increase CPU speed
(B) Allocate registers
(C) Manage RAM
(D) Store output of one device to use later by another device
7. . Which I/O technique is fastest for large data transfers?
(A) Programmed I/O
(B) DMA
(C) Interrupt-driven I/O
(D) Sequential I/O
8. . A device driver is:
(A) Hardware component
(B) Memory manager
(C) CPU scheduler
(D) Software that controls a specific device
9. . Block devices transfer data in:
(A) Single characters
(B) CPU instructions
(C) Files only
(D) Fixed-size blocks
10. . Character devices transfer data:
(A) One character at a time
(B) In blocks
(C) Using DMA only
(D) Using files only
11. . Synchronous I/O requires:
(A) Only interrupts
(B) DMA for transfer
(C) CPU waits until I/O operation completes
(D) Memory management
12. . Asynchronous I/O allows:
(A) CPU to wait idle
(B) CPU to continue execution while I/O is in progress
(C) Files to be deleted
(D) Sequential access only
13. . Memory-mapped I/O means:
(A) CPU waits idle
(B) I/O device is mapped to memory address space
(C) Files are stored in memory
(D) DMA only
14. . Polling is a method where:
(A) DMA transfers data automatically
(B) CPU waits for interrupt
(C) CPU repeatedly checks device status
(D) Files are stored sequentially
15. . Which of the following is an advantage of interrupt-driven I/O over programmed I/O?
(A) Simpler implementation
(B) CPU utilization is higher
(C) CPU always waits idle
(D) Less control over devices
16. . I/O buffers are used to:
(A) Store files permanently
(B) Increase CPU registers
(C) Temporarily hold data between CPU and device
(D) Schedule CPU
17. . Double buffering improves:
(A) CPU speed only
(B) Device utilization and system performance
(C) Memory capacity
(D) File storage
18. . Direct I/O means:
(A) CPU reads/writes directly to/from I/O device
(B) Data is transferred via buffer
(C) CPU uses DMA
(D) CPU waits idle
19. . Channel I/O is used in:
(A) Large mainframe systems
(B) Personal computers
(C) Laptops only
(D) Microcontrollers
20. . The main goal of I/O systems is to:
(A) Increase CPU speed only
(B) Ensure efficient and reliable communication between CPU and devices
(C) Manage memory
(D) Delete files automatically