01Full mock 1
30 questions across all ten OS topics – scheduling, paging, page replacement, disk, Banker's algorithm, fork() and races – with negative marking.
- questions
- 30
- minutes
- 50
- sections
- 2
- Numericals and code 20
- Concepts 10
Technical tests
Operating Systems Online Test
Schedule processes on Gantt charts, trace page replacement and disk heads, run fork() and thread puzzles – every answer is computed or executed.
- Topics
- 11
- Practice sets
- 33
- Full mocks
- 4
- Questions
- 495
Operating systems are tested in almost every campus placement technical round, in systems interviews and in GATE CSE, where scheduling, memory and synchronisation problems carry many marks. Here you schedule processes on drawn Gantt charts, trace page frames and disk-head movement, predict what fork() and thread programs print and check the Banker's algorithm. Every number was computed by a simulator and every program was compiled and run.
Full mocks
Test yourself like the real round
Placement-style mocks · −0.25 per wrong answer
02Full mock 2
30 fresh questions – no overlap with Mock 1 – from exec() and Belady's anomaly to C-SCAN timing, semaphores and pthreads.
- questions
- 30
- minutes
- 50
- sections
- 2
- Numericals and code 18
- Concepts 12
GATE CSE pattern · MCQ −⅓ / −⅔, no negative on MSQ and NAT
01GATE mock 1
GATE20 questions, 30 marks in the GATE CSE pattern – MCQ, MSQ and NAT, 1- and 2-mark questions, negative marks on MCQs only.
- questions
- 20
- marks
- 30
- minutes
- 55
- MCQ 10
- MSQ 4
- NAT 6
- Calculator
02GATE mock 2
GATE20 questions, 30 marks in the GATE CSE pattern – MCQ, MSQ and NAT, 1- and 2-mark questions, negative marks on MCQs only.
- questions
- 20
- marks
- 30
- minutes
- 55
- MCQ 10
- MSQ 4
- NAT 6
- Calculator
Topic-wise practice
Choose a topic and level
01OS Basics and System Calls
What a kernel does, user and kernel mode, system calls and traps, interrupts and DMA, booting, kernel designs, virtual machines and containers.
02Processes, Threads and fork()
Process states and the PCB, fork(), exec() and wait() output puzzles, zombies and orphans, threads vs processes, IPC, schedulers and copy-on-write.
03CPU Scheduling Algorithms
FCFS, SJF, SRTF, Round Robin, Priority, HRRN and multilevel queues on drawn Gantt charts – waiting, turnaround and response time, context switches, burst prediction and real-time scheduling.
04Process Synchronization and Semaphores
Race conditions and the critical-section problem, Peterson's solution, test-and-set, mutexes and semaphores, producer–consumer, readers–writers, dining philosophers, monitors and condition variables.
05Deadlocks and Banker's Algorithm
The four Coffman conditions, resource-allocation graphs, prevention, avoidance with the Banker's algorithm (safety and request checks), detection, recovery and minimum-resource numericals.
06Memory Management and Paging
Logical vs physical addresses, contiguous allocation (first, best, worst, next fit), fragmentation, paging and address translation, page-table size, TLB and effective access time, multilevel and inverted page tables, segmentation and the buddy system.
07Virtual Memory and Page Replacement
Demand paging and page faults, FIFO, LRU, Optimal and clock replacement traced on reference strings, Belady's anomaly, effective access time with faults, thrashing, working sets and frame allocation.
08File Systems and Disk Scheduling
Files, directories and inodes, hard and symbolic links, contiguous, linked, FAT and indexed allocation, free-space bitmaps, journaling, RAID, and FCFS, SSTF, SCAN, C-SCAN, LOOK and C-LOOK disk scheduling on drawn head paths.
09Threads and Concurrency in Code
Creating and joining threads in Java, C++ and Python, thread safety, atomics, locks and reentrancy, latches, queues and executors, asyncio, memory visibility, possible outcomes under interleaving and Amdahl's law.
10Linux Commands and Shell
Files and permissions (chmod, umask, setuid, sticky bit), processes and signals, pipes and redirection, grep, sort, uniq, cut, awk, sed and tr, quoting, exit statuses, environment variables, cron and system tools.
11GATE-Style OS Questions (MSQ & NAT)
Multiple-select and numerical-answer OS questions in the GATE CSE pattern: safe sequences, schedules, page faults, disk movement, interleavings, page tables and access times.
No sets match this filter.