Q. Four jobs J1, J2, J3 and J4 are waiting to be run. Their expected run times are 9, 6, 3 and 5 respectively. In order to minimize average response time, the jobs should be run in the order:

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Q. Suppose it takes 100 ns to access page table and 20 ns to access associative memory. If the average access time is 28 ns, the corresponding hit rate is:

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Q. N processes are waiting for I/O. A process spends a fraction p of its time in I/O wait state. The CPU utilization is given by:

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Q. If holes are half as large as processes, the fraction of memory wasted in holes is:

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Q. An example of a non pre-emptive scheduling algorithm is:

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Q. An example of distributed OS is:

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Q. In which of the following, ready to execute processes must be present in RAM?

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Q. If the executing program size is greater than the existing RAM of a computer, it is still possible to execute the program if the OS supports:

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Q. Files that are related to input/output and are used to model serial I/O devices such as terminals, printers and networks are called :

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Q. An example of a possible file attribute is:

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Q. An example of a non-preemptive CPU scheduling algorithm is:

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Q. There are ‘n’ processes in memory. A process spends a fraction ‘p’ of its time waiting for I/O to complete. The CPU utilization is given by:

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Q. With 64 bit virtual addresses, a 4KB page and 256 MB of RAM, an inverted page table requires:

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Q. A computer has 6 tape drives with ‘n’ processes competing for them. Each process may need two drives. For which values of ‘n’ is the system deadlock free ?

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Q. A program has five virtual pages, numbered from 0 to 4. If the pages are referenced in the order 012301401234, with three page frames, the total number of page faults with FIFO will be equal to:

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Q. Average process size=s bytes. Each page entry requires e bytes. The optimum page size is given by:

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Q. The aging algorithm with a=0.5 is used to predict run times. The previous four runs from oldest to most recent are 40, 20, 20 and 15 msec. The prediction for the next time will be:

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Q. Moving process from main memory to disk is called:

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Q. Part of a program where the shared memory is accessed and which should be executed indivisibly, is called:

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Q. Windows is a .................. operating system.

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