Paper 2 CS · UNIT 05 · MOCK TEST

System Software and Operating System — Mock Test 13

25 questions · about 30 minutes. Press End Mock any time to see your score and the correct answers.

0 / 25 answered 00:00

Q1.

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 20 nanoseconds. What will be the effective memory access time given an 80 % hit ratio?

A110 nanoseconds B116 nanoseconds C200 nanoseconds D100 nanoseconds

Q2.

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?

A<p0, p1, p2> B<p1, p0, p2> C<p2, p1, p0> D<p0, p2, p1>

Q3.

Which of the following interprocess communication model is used to exchange messages among co-operative processes?

AShared memory model BMessage passing model CShared memory and message passing model DQueues

Q4.

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.

A4,0 B5.66,1.66 C5.66,0 D7,2

Q5.

Which of the following methods are used to pass any number of parameters to the operating system through system calls?

ARegisters BBlock or table in main memory CStack DBlock in main memory and stack

Q6.

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

(d) A process switches from Ready to Waiting state

Choose the correct option :

A(a) and (b) only B(a) and (d) only C(c) and (d) only D(a). (b), (c) only

Q7.

For a magnetic disk with concentric circular tracks, the seek latency is not linearly proportional to the seek distance due to

Anon-uniform distribution of requests Barm starting or stopping inertia Chigher capacity of tracks on the periphery of the platter DMore than one of the above

Q8.

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 taken to satisfy all requests 1 ms if it takes to move from the cylinder to adjacent one and the shortest seek time first policy is used?

A357 ms B238 ms C276 ms D119 ms

Q9.

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.

A(a)-(i); (b)-(ii); (c)-(iii); (d)-(iv) B(a)-(iii); (b)-(i); (c)-(iv); (d)-(ii) C(a)-(ii); (b)-(i); (c)-(iv); (d)-(iii) D(a)-(ii); (b)-(iv); (c)-(iii); (d)-(i)

Q10.

Which of the following are NOT shared by the threads of the same process?

(a) Stack

(b) Registers

(d) Message queue

A(a) and (d) B(b) and (c) C(a) and (b) D(a), (b) and (c)

Q11.

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 and optimal page replacement for referencing the string?

A2 B0 C1 D3

Q12.

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 time first scheduling algorithm? Do not count the context switches at time zero and at the end.

A4 B2 C3 D1

Q13.

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?

A28 B12 C2 D42

Q14.

The minimum number of page frames that must be allocated to a running process in a virtual memory environment is determined by

Apage size Bphysical size of memory Cthe instruction set architecture Dnumber of processes in memory

Q15.

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?

A5 B4 C3 D6

Q16.

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?

Acat *.ch | wc -l Bcat *.[c-h] | wc -l Ccat *.[ch], ls -1 Dcat *.[ch] | wc -l

Q17.

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 system dynamically.

A(i) only B(ii) only CNeither (i) nor (ii) DBoth (i) and (ii)

Q18.

In Linux operating system environment _______ command is used to print a file.

Aprint Bptr Cpr Dlpr

Q19.

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.

(iii) Both Readers and Writers are given exclusive access to shared objects.

A(i) only B(ii) only C(iii) only DBoth (ii) and (iii)

Q20.

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 deadlock is

A3 B4 C5 D6

Q21.

Dirty bit is used to show the

Awrong page Bpage with corrupted data Cpage with low frequency occurrence Dpage that is modified after being loaded into cache memory

Q22.

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, assume FIFO Page Replacement Algorithm is used then the number of page faults that occur to complete the execution of process P is

A4 B3 C5 D6

Q23.

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.

A0 B4 C12 D6

Q24.

Suppose P, Q, and R are cooperating processes satisfying Mutual Exclusion conditions. Then, if Q the process is executing in its critical section then

ABoth ' P ' and 'R ' execute in the critical section. BNeither ' P ' nor ' R ' executes in their critical section. C'P' executes in the critical section. D' R ' executes in the critical section.

Q25.

A process residing in Main Memory and Ready and Waiting for execution is kept on?

AExecution Queue BJob Queue CReady Queue DWait Queue