CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
For real-time scheduling, which dynamic-priority algorithm commonly gives highest priority to the job with the closest deadline?
A. FCFS
B. Round Robin
C. SJF without deadlines
D. Earliest Deadline First (EDF)
Correct Answer: D
EDF schedules the task whose deadline is earliest.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which scheduling method allows processes to move between queues according to behavior and aging?
A. Multilevel feedback queue
B. Simple FCFS
C. Static partitioning
D. Contiguous allocation
Correct Answer: A
Multilevel feedback queues adapt process priority and queue placement dynamically.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which scheduling approach uses multiple ready queues for different classes of processes?
A. Disk mirroring
B. Multilevel queue scheduling
C. FCFS only
D. Optimal page replacement
Correct Answer: B
Multilevel queue scheduling separates classes such as foreground and background jobs.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which scheduler may temporarily remove processes from memory and later restore them?
A. Printer scheduler
B. File allocator
C. Medium-term scheduler
D. Long-term scheduler only
Correct Answer: C
The medium-term scheduler is associated with swapping/suspending processes.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which scheduler selects the next ready process for the CPU very frequently?
A. Long-term scheduler
B. File scheduler
C. Boot scheduler
D. Short-term scheduler
Correct Answer: D
The short-term CPU scheduler runs frequently to choose the next execution candidate.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which scheduler controls the degree of multiprogramming by deciding which jobs enter the ready pool?
A. Long-term scheduler
B. Short-term scheduler
C. Disk scheduler
D. Page replacement algorithm
Correct Answer: A
The long-term scheduler admits jobs and influences how many processes compete for resources.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
What is dispatch latency?
A. Time to translate a virtual address
B. Time needed to stop one process and start another
C. Time to copy a file
D. Time to format a disk
Correct Answer: B
Dispatch latency is the scheduler/dispatcher overhead before the chosen process begins running.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which component actually gives control of the CPU to the process selected by the short-term scheduler?
A. Loader only
B. File manager
C. Dispatcher
D. Linker
Correct Answer: C
The dispatcher performs the context switch and transfers CPU control to the selected process.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which scheduling metric is especially important for interactive systems?
A. Tape rewind time
B. File size
C. Boot sector count
D. Response time
Correct Answer: D
Interactive users care about how quickly the system first responds to a request.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which scheduling criterion measures how long a process spends in the ready queue?
A. Waiting time
B. Turnaround time
C. Disk latency
D. Service uptime
Correct Answer: A
Waiting time is the total duration a process waits for CPU service in the ready queue.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which scheduling criterion measures the time from process submission to completion?
A. Page-fault time
B. Turnaround time
C. Response time
D. Seek time
Correct Answer: B
Turnaround time equals completion time minus arrival/submission time.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which technique gradually raises the priority of waiting processes to reduce starvation?
A. Spooling
B. Journaling
C. Aging
D. Paging
Correct Answer: C
Aging increases priority over time so long-waiting tasks eventually run.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which scheduling problem can occur with strict priority scheduling?
A. Elimination of context switches
B. Automatic deadlock recovery
C. No ready queue
D. Starvation of low-priority processes
Correct Answer: D
Low-priority processes may wait indefinitely if higher-priority work keeps arriving.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
In Round Robin scheduling, an excessively small time quantum mainly causes:
A. High context-switch overhead
B. Deadlock prevention
C. Zero waiting time
D. No preemption
Correct Answer: A
Very small quanta create frequent context switches, increasing overhead.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
In Round Robin scheduling, if the time quantum becomes extremely large, the behavior approaches:
A. Lottery scheduling
B. FCFS
C. SRTF
D. Priority scheduling with aging
Correct Answer: B
A very large quantum lets each process run nearly to completion in arrival order.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which scheduling algorithm is widely associated with time-sharing systems?
A. Batch-only SJF
B. Banker's algorithm
C. Round Robin
D. Non-preemptive FCFS only
Correct Answer: C
Round Robin gives each ready process a time quantum in cyclic order.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
What is the preemptive version of Shortest Job First called?
A. FCFS
B. Highest Response Ratio Next
C. FIFO paging
D. Shortest Remaining Time First (SRTF)
Correct Answer: D
SRTF always favors the process with the least remaining CPU time.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
If CPU burst times are known accurately, which non-preemptive algorithm minimizes average waiting time for a fixed set of jobs?
A. Shortest Job First (SJF)
B. FCFS
C. Round Robin
D. Random scheduling
Correct Answer: A
SJF gives priority to the shortest CPU burst and is optimal for average waiting time under ideal assumptions.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which scheduling algorithm is well known for the convoy effect?
A. Earliest Deadline First
B. FCFS
C. Round Robin
D. Multilevel feedback queue
Correct Answer: B
A long CPU-bound job in FCFS can make many short jobs wait, creating the convoy effect.
CSS - PMS - CCE - PCS - Basic Computing
Operating Systems
Which scheduling algorithm executes processes in the order they arrive?
A. Round Robin
B. Priority aging
C. First-Come, First-Served (FCFS)
D. Shortest Remaining Time First
Correct Answer: C
FCFS serves ready processes in arrival order.