PPSC Lecturer Computer Science Past Paper Dated: 2015
1- Which module gives control of the CPU to the process selected by the short-term scheduler?
A. Dispatcher
B. Interrupt
C. Scheduler
D. None of these
View Answer
Answer : A. Dispatcher
Description
2- The processes that are residing in main memory for execution are kept on a list called:
A. Job queue
B. Ready queue
C. Execution queue
D. Process queue
View Answer
Answer : B. Ready queue
Description
3- The interval from the time of submission of a process to the time of completion is termed as:
A. Throughput
B. Response time
C. Waiting time
D. Turnaround time
View Answer
Answer : D. Turnaround time
Description
4- Which scheduling algorithm allocates the CPU first to the process that requests the CPU first?
A. First-come first-served scheduling
B. Shortest job scheduling
C. Priority scheduling
D. None of these
View Answer
Answer : A. First-come first-served scheduling
Description
5- In priority scheduling algorithm:
A. CPU is allocated to the process with highest priority
B. CPU is allocated to the process with lowest priority
C. Equal priority processes cannot be scheduled
D. None of these
View Answer
Answer : A. CPU is allocated to the process with highest priority
Description
6- In priority scheduling algorithm, when a process arrives at the ready queue, its priority is compared with the priority of:
A. Parent process
B. Init process
C. Currently running process
D. All processes
View Answer
Answer : C. Currently running process
Description
7- Time quantum is defined in:
A. Round robin scheduling algorithm
B. Shortest job scheduling algorithm
C. Priority scheduling algorithm
D. Multilevel queue scheduling algorithm
View Answer
Answer : A. Round robin scheduling algorithm
Description
8- In multilevel feedback scheduling algorithm:
A. A process can move to a different classified ready queue
B. Classification of ready queue is permanent
C. Processes are not classified into groups
D. None of the mentioned
View Answer
Answer : A. A process can move to a different classified ready queue
Description
9- Which one of the following cannot be scheduled by the kernel?
A. Process
B. Kernel level thread
C. User level thread
D. None of these
View Answer
Answer : C. User level thread
Description
10- A process refers to 5 pages, A, B, C, D, E in the order: A, B, C, D, A, B, E, A, B, C, D, E. If the page replacement algorithm is FIFO, the number of page transfers with an empty internal store of 3 frames is:
A. 7
B. 8
C. 9
D. 10
View Answer
Answer : C. 9
Description
11- A memory page containing a heavily used variable that was initialized very early and is in constant use is removed and then the page replacement algorithm used is:
A. LFU
B. LRU
C. FIFO
D. None of these
View Answer
Answer : C. FIFO
Description
12- Users are ______ that their processes are running on a paged system.
A. Aware
B. Unaware
C. Informed
D. None of these
View Answer
Answer : B. Unaware
Description
13- The aim of creating page replacement algorithms is to:
A. Replace pages faster
B. Increase the page fault rate
C. Decrease the page fault rate
D. To allocate multiple pages to processes
View Answer
Answer : C. Decrease the page fault rate
Description
14- A FIFO replacement algorithm associates with each page the ______.
A. Time it was brought into memory
B. Size of the page in memory
C. Page after and before it
D. All of these
View Answer
Answer : A. Time it was brought into memory
Description
15- Optimal page - replacement algorithm is:
A. Replace the page that has been used for a long time
B. Replace the page that has not been used for a long time
C. Replace the page that will not be used for a long time
D. None of these
View Answer
Answer : C. Replace the page that will not be used for a long time
Description
16- Optimal page - replacement algorithm is difficult to implement, because:
A. It is too complex
B. It is extremely expensive
C. It requires a lot of information
D. It requires future knowledge of the reference string
View Answer
Answer : D. It requires future knowledge of the reference string
Description
17- LRU page - replacement algorithm associates with each page the ______.
A. Time it was brought into memory
B. The time of that page is last use
C. Page after and before it
D. All of these
View Answer
Answer : B. The time of that page is last use
Description
18- For 3 page frames, the following is the reference string: 7 0 1 20 3 0 4 2 3 0 3 2 1 2 0 1 7 0 1; How many page faults does the LRU page replacement algorithm produce?
A. 10
B. 11
C. 12
D. 15
View Answer
Answer : C. 12
Description
19- CPU fetches the instruction from memory according to the value of:
A. Program counter
B. Status register
C. Instruction register
D. Program status word
View Answer
Answer : A. Program counter
Description
20- A memory buffer used to accommodate a spooled differential is called: