Threading and Multithreading MCQs: Concepts and Implementation

Test your understanding of threading and multithreading with this MCQ exam. Explore core concepts, implementations, synchronization and performance optimization techniques.

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  • 📋 Total Questions: 30
  • Time Limit: 30 minutes
  • 📝 Marking Scheme: +1 for each correct answer. No negative marking.
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1. What is a thread in the context of operating systems?

  • A process that runs in isolation
  • The smallest unit of execution within a process
  • A collection of processes sharing resources
  • A virtual representation of system memory

2. Which of the following best describes multithreading?

  • Running multiple processes simultaneously
  • Running multiple threads within a single process
  • Allocating memory to different programs
  • Scheduling tasks in sequential order

3. What is the main advantage of using multithreading in applications?

  • Improved memory usage
  • Faster single-threaded performance
  • Increased responsiveness and parallelism
  • Reduced CPU usage

4. What is a key challenge of multithreading?

  • Memory allocation issues
  • Synchronization and avoiding race conditions
  • Low processor utilization
  • Redundant resource usage

5. Which of the following is an example of thread-safe operation?

  • Reading from a shared variable without locks
  • Modifying shared data with proper synchronization
  • Writing to global memory without checks
  • Accessing a file without considering concurrent threads

6. In Java, which class is commonly used to create threads?

  • ThreadPool
  • Thread
  • Runnable
  • Executor

7. What is the state of a thread when it is waiting for a resource?

  • Running
  • Waiting
  • Terminated
  • Blocked

8. What does context switching refer to in multithreading?

  • Switching between user and kernel modes
  • Switching the CPU's focus between threads
  • Allocating resources to a process
  • Synchronizing shared memory

9. Which threading model maps multiple threads to multiple processors?

  • One-to-one model
  • Many-to-one model
  • Many-to-many model
  • Kernel-level model

10. What mechanism prevents two threads from accessing shared resources simultaneously?

  • Semaphore
  • Mutex
  • Critical section
  • All of the above

11. In Python, which module is used for creating threads?

  • multiprocessing
  • threading
  • asyncio
  • concurrent.futures

12. Which of the following is not a thread state?

  • Ready
  • Waiting
  • Running
  • Suspended

13. What is a race condition?

  • A condition where threads compete for CPU time
  • A scenario where the outcome depends on the thread execution order
  • A type of thread-safe execution
  • An error in thread termination

14. What is the primary use of a thread pool?

  • To allocate memory to processes
  • To manage multiple threads efficiently
  • To handle file I/O operations
  • To synchronize thread execution

15. Which of the following is a lightweight process?

  • Thread
  • Task
  • Process
  • Job

16. Deadlock in multithreading occurs when:

  • Threads execute simultaneously
  • Threads wait indefinitely for resources held by each other
  • Thread priorities are ignored
  • All threads terminate normally

17. The term "thread priority" refers to:

  • The order of thread execution based on importance
  • The speed of thread execution
  • The memory allocated to threads
  • The total number of active threads

18. What is a daemon thread in Java?

  • A thread that runs in the background and terminates when the program ends
  • A thread that handles user requests
  • A thread that prevents deadlocks
  • A thread with the highest priority

19. Which of these is not a synchronization mechanism?

  • Semaphore
  • Monitor
  • Mutex
  • Context switch

20. In C++, which library provides support for multithreading?

  • std::thread
  • pthreads
  • OpenMP
  • All of the above

21. What is the primary purpose of a lock in multithreading?

  • To increase execution speed
  • To prevent simultaneous access to shared resources
  • To allow threads to communicate
  • To reduce memory usage

22. What does GIL stand for in Python threading?

  • Global Instruction Lock
  • Global Interpreter Lock
  • General Incremental Lock
  • Generic Interface Library

23. Which scheduling algorithm is commonly used in multithreading?

  • First-Come-First-Served
  • Round-Robin
  • Shortest Job Next
  • Longest Job First

24. Which of the following is a disadvantage of multithreading?

  • Increased resource utilization
  • Simplified program logic
  • Increased complexity in debugging
  • Enhanced responsiveness

25. The main thread in a multithreaded program is:

  • The thread that creates child threads
  • A background thread
  • The last thread to terminate
  • A low-priority thread

26. Which of the following can cause a thread to terminate?

  • Completing its task
  • Calling the terminate() function
  • Receiving a signal from the operating system
  • All of the above

27. What is thread starvation?

  • Threads being unable to access shared memory
  • High-priority threads preventing low-priority threads from executing
  • Threads competing for CPU resources
  • Synchronization mechanisms failing

28. Thread-local storage is used for:

  • Sharing memory between threads
  • Storing data unique to each thread
  • Allocating memory to all threads
  • Managing thread priorities

29. Which of the following conditions is necessary for a deadlock to occur?

  • Circular wait
  • Mutual exclusion
  • Hold and wait
  • All of the above

30. What is the main goal of thread synchronization?

  • To ensure threads execute in order of creation
  • To prevent conflicts and inconsistencies in shared resources
  • To allocate CPU time equally among threads
  • To improve memory allocation efficiency