Operating System MCQs

Bounded-capacity buffering permits only a fixed number of queued messages.
A sender may have to wait when all available buffer slots are occupied.

A zero-capacity link stores no waiting messages, so send and receive must synchronize directly.
This interaction is commonly called a rendezvous.

Inter-process communication provides mechanisms for data sharing, event notification, and synchronization.
Independent execution alone cannot safely coordinate related tasks.

Shared memory exposes a common memory region that cooperating processes access directly.
After setup, data exchange can occur without a kernel call for every individual item.

A process whose CPU burst is shorter than the quantum releases the CPU before the timer expires.
Round robin then behaves with very little time-slice preemption for that workload.

A multilevel queue scheduler partitions processes into fixed classes such as interactive and batch.
Processes do not normally move between those queues.

A multilevel feedback queue changes a process's queue and priority according to CPU usage and waiting behavior.
This flexibility can favor short interactive work while still serving long jobs.

A Gantt chart displays the execution timeline produced by a scheduling algorithm.
It helps calculate completion, waiting, turnaround, and response times.

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.

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.

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.

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.