41. What is the purpose of the 'inode' in Linux/Unix?
- a) Stores metadata about a file (permissions, size, etc.)
- b) Manages CPU scheduling
- c) Handles network connections
- d) Encrypts disk partitions
Answer: A - Each file/directory has an inode containing its attributes (except the name).
42. Which of these is a page replacement algorithm?
- a) LRU (Least Recently Used)
- b) FCFS (First Come First Serve)
- c) SJF (Shortest Job First)
- d) Priority Scheduling
Answer: A - LRU replaces the page not used for the longest time to minimize page faults.
43. What is the main function of the 'bootloader'?
- a) Loads the OS kernel into memory at startup
- b) Manages user logins
- c) Compresses system files
- d) Scans for viruses
Answer: A - Examples include GRUB (Linux) and NTLDR (Windows).
44. Which Windows feature isolates applications for security?
- a) Sandbox
- b) Firewall
- c) BitLocker
- d) Task Manager
Answer: A - Sandbox restricts app access to system resources.
45. What is 'spooling' in OS?
- a) Temporarily storing data for devices like printers
- b) A type of memory fragmentation
- c) CPU overheating protection
- d) Network packet routing
Answer: A - Spooling (Simultaneous Peripheral Operations Online) queues print jobs.
46. Which command terminates a process in Linux?
- a) kill
- b) stop
- c) exit
- d) rm
Answer: A - kill [PID] sends termination signals (e.g., kill -9 for force kill).
47. What is 'paging' in memory management?
- a) Dividing memory into fixed-size blocks called pages
- b) Compressing RAM contents
- c) Sorting files alphabetically
- d) Encrypting swap space
Answer: A - Paging avoids external fragmentation by using equal-sized memory units.
48. Which of these is a multi-user OS?
- a) Unix
- b) MS-DOS
- c) Windows 3.1
- d) Android (single-user by default)
Answer: A - Unix/Linux allow multiple concurrent users via terminals.
49. What is 'belady's anomaly'?
- a) Increasing page faults when allocating more frames
- b) Deadlock during memory allocation
- c) CPU cache corruption
- d) Disk write errors
Answer: A - Occurs in FIFO page replacement under specific conditions.
50. Which Linux command displays manual pages?
- a) man
- b) help
- c) info
- d) doc
Answer: A - man ls shows the manual for the ls command.
51. What is 'RAID' in storage systems?
- a) Redundant Array of Independent Disks
- b) Random Access Indexed Data
- c) Read-Only Memory Allocation
- d) Real-time Application Interface
Answer: A - RAID combines disks for performance/redundancy (e.g., RAID 0, RAID 1).
52. Which Windows tool checks disk errors?
- a) chkdsk
- b) defrag
- c) format
- d) diskpart
Answer: A - chkdsk /f fixes filesystem errors.
53. What is 'preemptive scheduling'?
- a) OS can interrupt/take back CPU from a process
- b) Processes voluntarily release CPU
- c) CPU time is auctioned to processes
- d) Only kernel processes get CPU time
Answer: A - Used in Round Robin and priority scheduling.
54. Which file system is used by macOS?
- a) APFS (Apple File System)
- b) NTFS
- c) ext4
- d) FAT32
Answer: A - APFS replaced HFS+ in 2017 for better performance/encryption.
55. What is 'starvation' in process scheduling?
- a) Low-priority processes never get CPU time
- b) Excessive CPU overheating
- c) Memory leaks causing crashes
- d) Deadlocked processes
Answer: A - Common in priority-based scheduling without aging mechanisms.
56. Which command shows disk usage in Linux?
- a) df
- b) du
- c) free
- d) top
Answer: A - df -h displays free/used space in human-readable format.
57. What is 'copy-on-write' (COW)?
- a) Memory pages shared until modified
- b) Automatic file backups
- c) Disk mirroring technique
- d) Network packet duplication
Answer: A - Used in fork() to optimize memory usage.
58. Which Windows version introduced the Start menu?
- a) Windows 95
- b) Windows 3.1
- c) Windows XP
- d) Windows 10
Answer: A - Revolutionary GUI feature in Windows 95.
59. What is 'context switching'?
- a) Saving/restoring CPU state when switching processes
- b) Changing desktop themes
- c) Switching between user/kernel modes
- d) Altering file permissions
Answer: A - Overhead occurs due to register/memory updates.
60. Which Linux command changes file ownership?
- a) chown
- b) chmod
- c) usermod
- d) passwd
Answer: A - chown user:group file.txt modifies owner/group.