Round robin rotates through the ready queue and gives each process up to one time quantum.
It is widely used for time-sharing because it provides regular opportunities to run.
Shortest-remaining-time-first is the preemptive form of shortest-job-first.
A newly arrived process can preempt the current process if it has a shorter remaining burst.
Shortest-job-first selects the process with the smallest next CPU burst and is optimal for average waiting time.
Its practical difficulty is accurately predicting future CPU-burst lengths.
Correct Answer: A. Many short or I/O-bound processes wait behind one long CPU-bound process
Explanation:
The convoy effect occurs when a long CPU burst at the front delays many shorter jobs.
It can reduce device and CPU utilization because processes progress in an inefficient group.
First-come, first-served uses a FIFO ready queue and selects the earliest arrival.
It is simple but may produce long waits when an early CPU-bound job runs first.
Correct Answer: C. When it terminates or blocks voluntarily
Explanation:
A nonpreemptive scheduler does not forcibly remove the processor from a running process.
The scheduling decision is deferred until the process exits the CPU or enters a waiting state.
Correct Answer: B. The operating system may take the CPU from a running process before it finishes its CPU burst
Explanation:
Preemptive scheduling permits the kernel to interrupt a running process and reassign the processor.
This supports responsiveness and priority enforcement but adds synchronization and switching concerns.
Response time measures the delay from a request until the system produces the first observable response.
It is especially important for interactive and time-sharing systems.
Turnaround time covers the entire interval from job submission or arrival to completion.
It includes waiting, execution, and I/O delays experienced by the job.
Throughput is the number of processes or jobs completed per unit of time.
It evaluates total system productivity rather than the delay of one particular job.
CPU utilization indicates how effectively the processor is kept busy with productive execution.
It is a percentage rather than a per-process completion delay.
