Question

Consider the following statements about CPU scheduling :
A. First come, first serve can lead to the “convoy effect”

B. Shortest job first minimizes average waiting time

C. Round robin does not use time quantum for fairness

D. Priority scheduling may cause starvation

E. Multilevel feedback queue combines preemptive and non preemptive scheduling

Choose the correct answer from the options given below :

• A. A, B, C, E only
• B. B, C, D, E only
• C. A, B, D, E only
• D. A, C, D only

Hint:

If you see "Round Robin" and "No Time Quantum" in the same sentence, it's a trap! Round Robin is simply FCFS with a timer.

Answer 1

The Correct Option is C

We evaluate the accuracy of each statement based on standard operating system scheduling algorithms. 1. Evaluating Statements A, B, and C:
• A (FCFS): True. The convoy effect occurs when a large CPU-bound process blocks several smaller I/O-bound processes.
• B (SJF): True. Shortest Job First is proven to provide the minimum average waiting time for a given set of processes.
• C (RR): False. Round Robin specifically uses a time quantum (or time slice) to cycle through processes fairly. 2. Evaluating Statements D and E:
• D (Priority): True. High-priority processes can prevent low-priority processes from ever getting the CPU, a condition known as starvation.
• E (MLFQ): True. Multilevel Feedback Queues can use preemption for higher-level interactive queues while using non-preemptive logic for background, batch-oriented queues. 3. Final Logic: Statements A, B, D, and E are correct. C is incorrect because a time quantum is the defining feature of Round Robin.