System Software and Operating System – Previous Year Questions
336 questions from past UGC NET Paper 2 – Computer Science papers, each with the correct answer. Open any question for its explanation.
- Using the same table T (17 rows × 1024 columns, 32-bit word-addressable entries, 16 page frames of 1024 words each, LRU) and the same column-averaging program as above, now consider T stored in row-major format. How man…
- Using the same table T (17 rows × 1024 columns, 32-bit word-addressable entries, 16 page frames of 1024 words each, LRU) and the same column-averaging program as above, now consider T stored again in column-major format…
- Using the same table T (17 rows × 1024 columns, 32-bit word-addressable entries, 16 page frames of 1024 words each, LRU) and the same column-averaging program as above, what is the ratio of the number of page faults wit…
- A virtual memory system uses the first-in-first-out (FIFO) page replacement policy and allocates a fixed number of frames to a process. Assertion A: Increasing the number of page frames allocated to a process sometimes…
- Which of the following statement(s) is/are correct with respect to virtual memory? Statement I: Address translation is performed for every logical address used during the execution of a program. Statement II: A program…
- Which of the following statement(s) is/are correct with respect to virtual memory? Statement I: Address translation is performed for every logical address used during the execution of a program. Statement II: A program…
- A virtual memory system uses the first-in-first-out (FIFO) page replacement policy and allocates a fixed number of frames to a process. Assertion A: Increasing the number of page frames allocated to a process sometimes…
- Which of the statement is not true in regards to virtual memory? (i) The main objective for using virtual memory is to increase the effective capacity of the memory system. (ii) Size of the program can be as large as th…
- For the following page reference string: 4, 3, 2, 1, 4, 3, 5, 4, 3, 2, 1, 5 — the number of page faults that occur using the Least Recently Used (LRU) page replacement algorithm with frame size 3 is:
- Given memory access time as p nanoseconds and an additional q nanoseconds for handling a page fault, what is the effective memory access time if a page fault occurs once for every 100 instructions?
- Consider a machine with 16 GB of main memory and a 32-bit virtual address space, with page size 4 KB (frame size equals page size). If a process of size 34 KB is to be executed on this machine, what will be the size of…
- (Same machine as above: 16 GB main memory, 32-bit virtual address space, 4 KB page size.) What is the size of the page table needed to handle the given virtual address space, given that each page table entry is of size…
- (Same machine as above: 16 GB main memory, 32-bit virtual address space, 4 KB page size.) What is the minimum number of bits needed for the physical address?
- (Same machine as above: 16 GB main memory, 32-bit virtual address space, 4 KB page size.) The number of bits reserved for the frame offset is ____.
- (Same machine as above: 32-bit virtual address space, 4 KB page size.) Find the number of pages required for the given virtual address space.
- Consider a hypothetical machine with 3 pages of physical memory, 5 pages of virtual memory, and as the stream of page references by an application. If P and Q are the number of page faults the application would incur wi…
- For the page reference string 7, 0, 1, 2, 0, 3, 0, 4, 2, 3, 0, 3, 2, 1, 2, 0, 1, 7, 0, 1 with 3 page frames (initially empty), which page replacement algorithm produces the minimum number of page faults?
- Which of the following is incorrect for virtual memory?
- A memory management system has 64 pages with a page size of 512 bytes. Physical memory consists of 32 page frames. The number of bits required in the logical and physical addresses are respectively:
- Consider the page-reference string: 0 1 2 3 0 1 4 0 1 2 3 4. If the FIFO page-replacement algorithm is used, find the number of page faults for (a) 3 page frames and (b) 4 page frames, respectively.
- Indexed/grouped allocation (of disk blocks to a file) is useful because: (A) It supports both sequential and direct access. (B) The entire data block is available for data (no pointers embedded in it). (C) It does not r…
- A moving-head disk has 200 tracks, numbered 0 to 199. The head has just finished a request at track 125 and is currently at track 143 (so it is moving in the direction of increasing track numbers). The pending request q…
- A disk head is currently at cylinder 50. The pending requests, in the order they arrived, are for cylinders: 4, 34, 10, 7, 19, 73, 2, 15, 6, 20. Using the Shortest-Seek-Time-First (SSTF) disk scheduling policy, and give…
- Consider an operating system capable of loading and executing a single sequential user process at a time. The disk head scheduling algorithm used is first come first served (FCFS). If FCFS is replaced by shortest seek t…
- What is called journaling in a Linux operating system?
- In a file allocation system, the following allocation schemes are used: (A) Contiguous allocation, (B) Indexed allocation, (C) Linked allocation. Which allocation scheme(s) will NOT suffer from external fragmentation?
- Suppose a Linux file system has a block size of 2K bytes, a disk address is 32 bits, and an i-node contains the disk addresses of the first 12 direct blocks of a file, one single-indirect block, and one double-indirect…
- Consider a disk system having 60 cylinders. Disk requests are received by the disk drive for cylinders 10, 22, 20, 2, 40, 6, and 38, in that order. Assuming the disk head is currently at cylinder 20, what is the time ta…
- A disk queue has requests for I/O on cylinders 98, 183, 37, 122, 14, 124, 65, 67, with the disk head currently at cylinder 53. Using the shortest seek time first (SSTF) disk scheduling algorithm, what is the total head…
- Consider the following statements about UNIX file permissions: (A) UNIX provides three permission types — Read, Write and Execute. (B) UNIX provides three permission sets — Owner, Group and Others. Which of the above st…