Real-Time Operating Systems (RTOS) — MCQs – EE

1. What does RTOS stand for?
(A) Real-Time Operating System
(B) Random-Time Operating System
(C) Reliable Task Operating Software
(D) Rapid Task Organization System

2. The main function of an RTOS is to:
(A) Manage tasks and ensure timely execution
(B) Provide high graphics support
(C) Handle batch processing
(D) Perform database management

3. The key feature of an RTOS is:
(A) Deterministic response time
(B) Maximum throughput
(C) Non-preemptive scheduling
(D) Random task execution

4. In an RTOS, a task is:
(A) A basic unit of execution
(B) A hardware interrupt
(C) A file system process
(D) A communication port

5. The kernel of an RTOS is responsible for:
(A) Task scheduling and resource management
(B) Power generation
(C) Data storage
(D) Network transmission

6. A hard real-time system requires:
(A) Tasks to meet strict deadlines
(B) Occasional deadline misses
(C) High throughput only
(D) No time constraints

7. A soft real-time system allows:
(A) Occasional deadline misses without system failure
(B) No deadline misses
(C) Continuous background execution
(D) Non-deterministic behavior

8. Which of the following is a common example of a hard real-time system?
(A) Airbag deployment system
(B) Video streaming
(C) Word processing
(D) File backup

9. Which of the following is an example of a soft real-time system?
(A) Multimedia streaming
(B) Missile control
(C) Pacemaker
(D) Automotive braking

10. The scheduler in an RTOS decides:
(A) Which task runs at a given time
(B) How memory is allocated
(C) How interrupts are generated
(D) How peripherals are powered

11. The term context switching refers to:
(A) Saving and restoring task states during a switch
(B) Changing memory types
(C) Switching between hardware interfaces
(D) Resetting the processor

12. Which scheduling policy is most common in RTOS?
(A) Priority-based preemptive scheduling
(B) Round-robin scheduling
(C) Batch scheduling
(D) Shortest job first

13. In RTOS, an interrupt is:
(A) A signal that temporarily halts a task for urgent processing
(B) A software bug
(C) A type of memory
(D) A data structure

14. The interrupt service routine (ISR) is used to:
(A) Handle specific interrupt events quickly
(B) Schedule long background jobs
(C) Manage files
(D) Allocate system memory

15. Priority inversion occurs when:
(A) A high-priority task waits for a low-priority task
(B) A low-priority task preempts a high-priority one
(C) Multiple tasks run simultaneously
(D) Deadlock occurs between processes

16. A solution to priority inversion is:
(A) Priority inheritance protocol
(B) FIFO scheduling
(C) Disabling all interrupts
(D) Using non-preemptive scheduling

17. The task control block (TCB) stores:
(A) Information about a task’s state and context
(B) Only memory addresses
(C) Hardware configuration
(D) Stack pointer only

18. In RTOS, mutual exclusion (mutex) is used to:
(A) Prevent simultaneous access to shared resources
(B) Allocate additional memory
(C) Synchronize clocks
(D) Delay task execution

19. A semaphore in RTOS is used for:
(A) Task synchronization and resource management
(B) Data transmission
(C) Interrupt control
(D) Memory allocation

20. The term latency in RTOS refers to:
(A) Time delay between an event and system response
(B) Total processing time
(C) Memory access time
(D) Clock speed

21. The idle task in RTOS runs when:
(A) No other task is ready to execute
(B) Highest-priority task runs
(C) A hardware interrupt occurs
(D) A task is blocked

22. The RTOS tick represents:
(A) A fixed time interval for scheduling decisions
(B) A power cycle
(C) A CPU instruction
(D) An I/O operation

23. Which component handles task switching in RTOS?
(A) Kernel
(B) Timer
(C) Peripheral driver
(D) Bootloader

24. The real-time clock (RTC) in an RTOS is used for:
(A) Maintaining accurate system time
(B) Managing interrupts
(C) Allocating memory
(D) Scheduling tasks directly

25. The main goal of RTOS design is:
(A) Predictable and reliable task execution
(B) Maximum number of tasks
(C) Reduced memory usage only
(D) High network bandwidth

26. The determinism of an RTOS refers to:
(A) Consistency of response times
(B) Random response delays
(C) Task priority variation
(D) CPU frequency adjustment

27. The deadlock in RTOS occurs when:
(A) Two or more tasks wait indefinitely for resources
(B) CPU fails to execute tasks
(C) Memory is full
(D) System clock stops

28. Which of the following is a popular RTOS?
(A) FreeRTOS
(B) Windows 11
(C) Android OS
(D) macOS

29. Which of the following is commonly used in automotive systems?
(A) QNX Neutrino
(B) Linux Ubuntu
(C) Chrome OS
(D) Android

30. The major advantage of RTOS in embedded systems is:
(A) Real-time responsiveness and predictability
(B) High graphics performance
(C) Large memory management
(D) Reduced hardware complexity