Q. Consider n processes sharing the CPU in round robin fashion. Assuming that each process switch takes s seconds. What must be the quantum size q such that the overhead resulting from process switching is minimized but, at the same time each process is guaranteed to get its turn at the CPU at least every t seconds ? 

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Q. The virtual address generated by a CPU is 32 bits. The Translation Look-aside Buffer (TLB) can hold total 64 page table entries and  4-way set associative (i.e.with4-cache lines in the set). The page Sill' is 4 KB. The minimum size of TLB tag is

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Q. Consider a disk queue with request for input/output to block on cylinders

98,183,37,122,14, 124, 65, 67 in that order

Assume that disk head is  initially positioned at cylinder 53  and moving towards cylinder number 0. The total number of head movements using Shortest Seek lime First (SSTF) and SCAN algorithms are respectively

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Q. How much space will be required to store the bit map of a 1.3 GB disk with 512 bytes block size

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Q. Translation Look-aside Buffer (TLB) is

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Q. Simplest way of deadlock recovery is

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Q. Possible thread states in Windows 2000 operating system include

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Q. Which of the following conditions does not hold good for a solution to a critical section problem?

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Q. In a demand paging memory system, page table is held in registers. The time taken to service a page fault is 8 m.sec. If an empty frame is available or if the replaced page is not modified, and it takes 20 m.sec., if the replaced page is modified. What is the average access time to service a page fault assuming that the page to be replaced is modified 70% of the time?

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Q. The directory can be viewed as _______ that translates filenames into their directory entries.

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Q. Consider the following justifications for commonly using the two-level CPU scheduling :

I. It is used when memory is too small to hold all the ready processes.

II. Because its performance is same as that of the FIFO.

III. Because it facilitates putting some set of processes into memory and a choice is made from that.

IV. Because it does not allow to adjust the set of in-core processes.

Which of the following is true?

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Q. For the implementation of a paging scheme, suppose the average process size be x bytes, the page size be y bytes, and each page entry requires z bytes. The optimum page size that minimizes the total overhead due to the page table and the internal fragmentation loss is given by

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Q. Which methods are utilized to control the access to an object in multi-threaded programming?

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Q. Various storage devices used by an operating system can be arranged as follows in increasing order of accessing speed:

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Q. How many disk blocks are required to keep list of free disk blocks in a 16 GB hard disk with 1 kB block size using linked list of free disk blocks? Assume that the disk block number is stored in 32 bits.

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Q. Consider an imaginary disk with 40 cylinders. A request come to read a block on cylinder 11. While the seek to cylinder 11 is in progress, new requests come in for cylinders 1, 36, 16, 34, 9 and 12 in that order. The number of arm motions using shortest seek first algorithm is

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Q. An operating system has 13 tape drives. There are three processes PI, P2 & P3.1 Maximum requirement of PI is 11 tape drives, P2 is 5 tape drives and P3 is 8 tape drives. Currently, PI is allocated 6 tape drives, P2 is allocated 3 tape drives and P3 is allocated 2 tape drives. Which of the following sequences represent a safe state?

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Q. Monitor is an Interprocess Communication (IPC) technique which can be described as

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Q. A disk drive has 100 cylinders, numbered 0 to 99. Disk requests come to the disk driver for cylinders 12,26,24,4,42,8 and 50 in that order. The driver is currently serving a request at cylinder 24- A seek takes 6 msec per cylinder moved. How much seek time is needed for shortest seek time first (SSTF) algorithm ?

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Q. Let Pi and Pj be two processes, R be the set of variables read from memory, and W be the set variables written to memory. For the concurrent execution of two processes Pi and Pj, which of the following conditions is not true?

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