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.
Topic-wise mock tests
- Consider a paging system where translation looks aside buffer (TLB) a special type of associative memory is used with a hit ratio of 80%.. Assume that memory reference takes 80 nanoseconds and reference time to TLB is 2…
- A system has 12 tape drives. At time t0, p0 has maximum need 10 and holds 5, p1 needs 4 and holds 2, p2 needs 9 and holds 2. The system is in a safe state. Which is a safe sequence?
- Which of the following interprocess communication model is used to exchange messages among co-operative processes?
- With a 2 ms time slice and processes P1 (burst 3, arrival 0), P2 (4, 2), P3 (5, 5), find the average turnaround and waiting times under round robin.
- Which of the following methods are used to pass any number of parameters to the operating system through system calls?
- Identify the circumstances under which pre- emptive CPU scheduling is used : (a) A process switches from Running state to Ready state (b) A process switches from Waiting state to Ready state (c) A process completes its…
- For a magnetic disk with concentric circular tracks, the seek latency is not linearly proportional to the seek distance due to
- Consider a disk system with 100 cylinders. The requests to access the cylinders occur in the following sequence : 4, 34, 10, 7, 19, 73, 2, 15, 6, 20 Assuming that the head is currently at cylinder 50 , what is the time…
- Match List I with List II. List I: (a) Disk, (b) CPU, (c) Memory, (d) Interrupt. List II: (i) Thread, (ii) Signal, (iii) File system, (iv) Virtual address space.
- Which of the following are NOT shared by the threads of the same process? (a) Stack (b) Registers (c) Address space (d) Message queue
- Consider that a process has been allocated 3 frames and has a sequence of page referencing 1, 2, 1, 3, 7, 4, 5, 6, 3, 1 as . What shall be the difference in page faults for the above string using the algorithms of LRU a…
- Consider three CPU intensive processes, which require 10,20 and 30 units of time and arrive at times 0,2 and 6 respectively. How many context switches are needed if the operating system implements a shortest remaining t…
- At a particular time of computation, the value of a counting semaphore is 7. Then 20 P (wait) operations and 15 V (signal) operations are completed on this semaphore. What is the resulting value of the semaphore?
- The minimum number of page frames that must be allocated to a running process in a virtual memory environment is determined by
- A computer has six tape drives with (n) processes competing for them. Each process may need two drives. What is the maximum value of (n) for the system to be deadlock free?
- Which of the following UNIX/Linux pipes will ⋅c count the number of lines in all the files having h and as their extension in the current working directory?
- Which of the following statement/s is/are true? (i) Windows XP supports both peer-peer and client-server networks. (ii) Windows XP implements Transport protocols as drivers that can be loaded and unloaded from the syste…
- In Linux operating system environment _______ command is used to print a file.
- To overcome difficulties in Readers-Writers problem, which of the following statement/s is/are true? (i) Writers are given exclusive access to shared objects. (ii) Readers are given exclusive access to shared objects. (…
- Suppose a system has 12 instances of some resource with n processes competing for that resource. Each process may require 4 instances of the resource. The maximum value of n for which the system never enters into deadlo…
- Dirty bit is used to show the
- Suppose for a process P, reference to pages in order are (1,2,4,5,2,1,2,4). Assume that main memory can accomodate 3 pages and the main memory has already pages 1 and 2 in the order 1 - first, 2 - second. At this moment…
- Consider the following processes with CPU burst times in milliseconds (table below). The processes are scheduled with Round-Robin scheduling with a time quantum of 4 ms. The waiting time for P₄ is ___ ms.
- Suppose P, Q, and R are cooperating processes satisfying Mutual Exclusion conditions. Then, if Q the process is executing in its critical section then
- A process residing in Main Memory and Ready and Waiting for execution is kept on?
- ______ system call creates new process in Unix.
- At a particular time of computation, the value of a counting semaphore is 10. Then 12 P operations and “x” V operations were performed on this semaphore. If the final value of semaphore is 7, x will be :
- In a paged memory, the page hit ratio is 0.40. The time required to access a page in secondary memory is equal to 120 ns. The time required to access a page in primary memory is 15 ns. The average time required to acces…
- In a multi-user operating system, 30 requests are made to use a particular resource per hour, on an average. The probability that no requests are made in 40 minutes, when arrival pattern is a poisson distribution, is __…
- Normally user programs are prevented from handling I/O directly by I/O instructions in them. For CPUs having explicit I/O instructions, such I/O protection is ensured by having the I/O instructions privileged. In a CPU…