Q. Consider a uniprocessor computer system that has 2 processes and both of them alternate 10ms CPU bursts with 90ms I / O bursts. Both the processes were created at nearly the same time and can proceed in parallel. What is the scheduling strategy for this system that will result in the least CPU utilization (over a long period of time) ?

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Q. We have an operating system, which is capable of loading and executing a single sequential user process at a time. If the disk head scheduling algorithm which is initially First Come First Served (FCFS) is replaced by Shortest Seek Time First (SSTF) claimed by the vendor to give 50% better benchmark results then what is the expected improvement in the I / O performance of the user programs?

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Q. We have a uniprocessor machine where a set of n tasks with known run times r1, r2, r3,….rn are to be run. What will be the maximum throughput result of the processor scheduling algorithm?

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Q. Three CPU intensive processes requires 10, 20 and 30 time units and arrive at times 0, 2 and 6 respectively. The operating system implements a shortest remaining time first scheduling algorithm. Considering that the context switches at time zero and at the end are not counted the number of context switches are needed is ______.

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Q. What is the non - preemptive scheduling algorithm?

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Q. Which of the following statements are true?

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Q. On a single processor four jobs are to be executed. At time t = (0) + (jobs arrive in the order of A, B, C, D). The burst CPU time requirements are 4, 1, 8, 1 time units respectively.
Under Round Robin Scheduling with the time slice of 1 time unit the completion time of A is ______.

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Q. Interval between the time of submission and completion of the job is called

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Q. A scheduler which selects processes from secondary storage device is called

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Q. The scheduling in which CPU is allocated to the process with least CPU-burst time is called

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Q. The “turn-around” time of a user job is the

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Q. Program ‘preemption’ is

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Q. “Throughput” of a system is

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Q. Jobs which are admitted to the system for processing is called

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Q. ___________ is a technique of improving the priority of process waiting in Queue for CPU allocation.

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Q. .............. refers to a situation in which a process is ready to execute but is continuously denied access to a processor in deference to other processes.

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Q. Which of the following are the states of a five state process model?

i) Running ii) Ready iii) New iv) Exit v) Destroy

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Q. State which statement is true for Suspended process?

i) The process is not immediately available for execution.
ii) The process may be removed from suspended state automatically without removal order.

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Q. Following is/are the reasons for process suspension.

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Q. Match the following mechanisms for interrupting the execution of a process and their uses.

i) Interrupt a) Call to an operating system function
ii) Trap b) Reaction to an asynchronous external event
iii) Supervisor Call c) Handling of a error or an exception condition

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