Operating System MCQ Set 1
1. A process is thrashing if :
a) it spends a lot of time executing, rather than paging
b) it spends a lot of time paging, than executing
c) it has no memory allocated to it
d) none of the mentioned
Answer
Answer: b [Reason:] None.
2. Thrashing _______ the CPU utilization.
a) increases
b) keeps constant
c) decreases
d) none of the mentioned
Answer
Answer: c [Reason:] None.
3. A locality is :
a) a set of pages that are actively used together
b) a space in memory
c) an area near a set of processes
d) none of the mentioned
Answer
Answer: a [Reason:] None.
4. When a subroutine is called,
a) it defines a new locality
b) it is in the same locality from where it was called
c) it does not define a new locality
d) none of the mentioned
Answer
Answer: a [Reason:] None.
5. A program is generally composed of several different localities, which _____ overlap.
a) may
b) must
c) do not
d) must not
Answer
Answer: a [Reason:] None.
6. In the working set model, for :
2 6 1 5 7 7 7 7 5 1 6 2 3 4 1 2 3 4 4 4 3 4 3 4 4 4 1 3 2 3
if DELTA = 10, then the working set at time t1 (….7 5 1) is :
a) {1, 2, 4, 5, 6}
b) {2, 1, 6, 7, 3}
c) {1, 6, 5, 7, 2}
d) {1, 2, 3, 4, 5}
Answer
Answer: c [Reason:] None.
7. The accuracy of the working set depends on the selection of :
a) working set model
b) working set size
c) memory size
d) number of pages in memory
Answer
Answer: b [Reason:] None.
8. If working set window is too small :
a) it will not encompass entire locality
b) it may overlap several localities
c) it will cause memory problems
d) none of the mentioned
Answer
Answer: a [Reason:] None.
9. If working set window is too large :
a) it will not encompass entire locality
b) it may overlap several localities
c) it will cause memory problems
d) none of the mentioned
Answer
Answer: b [Reason:] None.
10. If the sum of the working – set sizes increases, exceeding the total number of available frames :
a) then the process crashes
b) the memory overflows
c) the system crashes
d) the operating system selects a process to suspend
Answer
Answer: d [Reason:] None.
11. Consider the following page reference string :
1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6
For LRU page replacement algorithm with 4 frames, the number of page faults is :
a) 10
b) 14
c) 8
d) 11
Answer
Answer: a [Reason:] None.
12. Consider the following page reference string :
1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6
For LRU page replacement algorithm with 5 frames, the number of page faults is :
a) 10
b) 14
c) 8
d) 11
Answer
Answer: c [Reason:] None.
13. Consider the following page reference string :
1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6
For FIFO page replacement algorithms with 3 frames, the number of page faults is :
a) 16
b) 15
c) 14
d) 11
Answer
Answer: a [Reason:] None.
14. Consider the following page reference string :
1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6
For FIFO page replacement algorithms with 4 frames, the number of page faults is :
a) 16
b) 15
c) 14
d) 11
Answer
Answer: c [Reason:] None.
15. Consider the following page reference string :
1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6
For Optimal page replacement algorithms with 3 frames, the number of page faults is :
a) 16
b) 15
c) 14
d) 11
Answer
Answer: d [Reason:] None.
Operating System MCQ Set 2
1. The disadvantage of real addressing mode is :
a) there is a lot of cost involved
b) time consumption overhead
c) absence of memory protection between processes
d) restricted access to memory locations by processes
Answer
Answer: c [Reason:] None.
2. Preemptive, priority based scheduling guarantees :
a) hard real time functionality
b) soft real time functionality
c) protection of memory
d) none of the mentioned
Answer
Answer: b [Reason:] None.
3. Real time systems must have :
a) preemptive kernels
b) non preemptive kernels
c) preemptive kernels or non preemptive kernels
d) neither preemptive nor non preemptive kernels
Answer
Answer: a [Reason:] None.
4. Event latency is :
a) the amount of time an event takes to occur from when the system started
b) the amount of time from the event occurance till the system stops
c) the amount of time from event occurance till the event crashes
d) the amount of time that elapses from when an event occurs to when it is serviced.
Answer
Answer: d [Reason:] None.
5. Interrupt latency refers to the period of time :
a) from the occurance of an event to the arrival of an interrupt
b) from the occurance of an event to the servicing of an interrupt
c) from arrival of an interrupt to the start of the interrupt service routine
d) none of the mentioned
Answer
Answer: c [Reason:] None.
6. Real time systems need to ____ the interrupt latency.
a) minimize
b) maximize
c) not bother about
d) none of the mentioned
Answer
Answer: a [Reason:] None.
7. The amount of time required for the scheduling dispatcher to stop one process and start another is known as ________
a) event latency
b) interrupt latency
c) dispatch latency
d) context switch
Answer
Answer: c [Reason:] None.
8. The most effective technique to keep dispatch latency low is to :
a) provide non preemptive kernels
b) provide preemptive kernels
c) make it user programmed
d) run less number of processes at a time
Answer
Answer: b [Reason:] None.
9. Priority inversion is solved by use of _______
a) priority inheritance protocol
b) two phase lock protocol
c) time protocol
d) all of the mentioned
Answer
Answer: a [Reason:] None.
Operating System MCQ Set 3
1. Earliest deadline first algorithm assigns priorities according to :
a) periods
b) deadlines
c) burst times
d) none of the mentioned
Answer
Answer: b [Reason:] None.
2. A process P1 has a period of 50 and a CPU burst of t1 = 25, P2 has a period of 80 and a CPU burst of 35. The total CPU utilization is :
a) 0.90
b) 0.74
c) 0.94
d) 0.80
Answer
Answer: c [Reason:] None.
3. In the above question, the priorities of P1 and P2 :
a) remain the same throughout
b) keep varying from time to time
c) may or may not be change
d) none of the mentioned
Answer
Answer: b [Reason:] None.
4. In Question number 2, can the two processes be scheduled using the EDF algorithm without missing their respective deadlines ?
a) Yes
b) No
c) Maybe
d) None of the mentioned
Answer
Answer: a [Reason:] None.
5. Using EDF algorithm practically, it is impossible to achieve 100 percent utilization due to :
a) the cost of context switching
b) interrupt handling
c) power consumption
d) all of the mentioned
Answer
Answer: a [Reason:] None.
6. T shares of time are allocated among all processes out of N shares in ____ scheduling algorithm.
a) rate monotonic
b) proportional share
c) earliest deadline first
d) none of the mentioned
Answer
Answer: b [Reason:] None.
7. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.
A will have ______ percent of the total processor time.
a) 20
b) 15
c) 50
d) none of the mentioned
Answer
Answer: c [Reason:] None.
8. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.
B will have ______ percent of the total processor time.
a) 20
b) 15
c) 50
d) none of the mentioned
Answer
Answer: b [Reason:] None.
9. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.
C will have ______ percent of the total processor time.
a) 20
b) 15
c) 50
d) none of the mentioned
Answer
Answer: a [Reason:] None.
10. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.
If a new process D requested 30 shares, the admission controller would :
a) allocate 30 shares to it
b) deny entry to D in the system
c) all of the mentioned
d) none of the mentioned
Answer
Answer: b [Reason:] None.
Operating System MCQ Set 4
1. Earliest deadline first algorithm assigns priorities according to :
a) periods
b) deadlines
c) burst times
d) none of the mentioned
Answer
Answer: b [Reason:] None.
2. A process P1 has a period of 50 and a CPU burst of t1 = 25, P2 has a period of 80 and a CPU burst of 35. The total CPU utilization is :
a) 0.90
b) 0.74
c) 0.94
d) 0.80
Answer
Answer: c [Reason:] None.
3. In the above question, the priorities of P1 and P2 :
a) remain the same throughout
b) keep varying from time to time
c) may or may not be change
d) none of the mentioned
Answer
Answer: b [Reason:] None.
4. In Question number 2, can the two processes be scheduled using the EDF algorithm without missing their respective deadlines ?
a) Yes
b) No
c) Maybe
d) None of the mentioned
Answer
Answer: a [Reason:] None.
5. Using EDF algorithm practically, it is impossible to achieve 100 percent utilization due to :
a) the cost of context switching
b) interrupt handling
c) power consumption
d) all of the mentioned
Answer
Answer: a [Reason:] None.
6. T shares of time are allocated among all processes out of N shares in ____ scheduling algorithm.
a) rate monotonic
b) proportional share
c) earliest deadline first
d) none of the mentioned
Answer
Answer: b [Reason:] None.
7. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.
A will have ______ percent of the total processor time.
a) 20
b) 15
c) 50
d) none of the mentioned
Answer
Answer: c [Reason:] None.
8. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.
B will have ______ percent of the total processor time.
a) 20
b) 15
c) 50
d) none of the mentioned
Answer
Answer: b [Reason:] None.
9. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.
C will have ______ percent of the total processor time.
a) 20
b) 15
c) 50
d) none of the mentioned
Answer
Answer: a [Reason:] None.
10. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.
If a new process D requested 30 shares, the admission controller would :
a) allocate 30 shares to it
b) deny entry to D in the system
c) all of the mentioned
d) none of the mentioned
Answer
Answer: b [Reason:] None.
Operating System MCQ Set 5
1. To schedule the processes, they are considered ___
a) infinitely long
b) periodic
c) heavy weight
d) light weight
Answer
Answer: b [Reason:] None.
2. If the period of a process is ‘p’, then the rate of the task is :
a) p2
b) 2*p
c) 1/p
d) p
Answer
Answer: c [Reason:] None.
3. The scheduler admits a process using :
a) two phase locking protocol
b) admission control algorithm
c) busy wait polling
d) none of the mentioned
Answer
Answer: c [Reason:] None.
4. The ______ scheduling algorithm schedules periodic tasks using a static priority policy with preemption.
a) earliest deadline first
b) rate monotonic
c) first cum first served
d) priority
Answer
Answer: b [Reason:] None.
5. Rate monotonic scheduling assumes that the :
a) processing time of a periodic process is same for each CPU burst
b) processing time of a periodic process is different for each CPU burst
c) periods of all processes is the same
d) none of the mentioned
Answer
Answer: a [Reason:] None.
6. In rate monotonic scheduling, a process with a shorter period is assigned :
a) a higher priority
b) a lower priority
c) higher & lower priority
d) none of the mentioned
Answer
Answer: a [Reason:] None.
7. There are two processes P1 and P2, whose periods are 50 and 100 respectively. P1 is assigned higher priority than P2. The processing times are t1 = 20 for P1 and t2 = 35 for P2. Is it possible to schedule these tasks so that each meets its deadline using Rate monotonic scheduling ?
a) yes
b) no
c) maybe
d) none of the mentioned
Answer
Answer: a [Reason:] None.
8. If a set of processes cannot be scheduled by rate monotonic scheduling algorithm, then :
a) they can be scheduled by EDF algorithm
b) they cannot be scheduled by EDF algorithm
c) they cannot be scheduled by any other algorithm
d) none of the mentioned
Answer
Answer: c [Reason:] None.
9. A process P1 has a period of 50 and a CPU burst of t1 = 25, P2 has a period of 80 and a CPU burst of 35. The total CPU utilization is :
a) 0.90
b) 0.74
c) 0.94
d) 0.80
Answer
Answer: c [Reason:] None.
10. Can the processes in the previous question be scheduled without missing the deadlines ?
a) Yes
b) No
c) Maybe
d) None of the mentioned
Answer
Answer: b [Reason:] None.
