GATE CS 2021 : Operating System Revision Quiz 4 for GATE & PSU CS Exams

Question 1

Suppose that a disk drive has 5000 cylinders, numbered 0 to 4999. The drive is currently serving a request at cylinder 143, and the previous request was at cylinder 125. The queue of pending requests, in FIFO order, is 86, 1470, 913, 1774, 948, 1509, 1022, 1750, and 130 . Starting from the current head position, what is the total distance (in cylinders) that the disk arm moves to satisfy all the pending requests, for each of the following disk- scheduling algorithms?
(i) FCFS
(ii) SSTF
(iii) SCAN

Question 2

The file access mechanism refers to the manner in which the records of a file may be accessed. There are several ways to access files, which among the following is not a file access method?

Question 3

Consider Longest Remaining Time First (LRTF) scheduling algorithm. There are 4 processes for which their process id, arrival time and burst time is given as

Completion time of P0 and P0 complete its execution after completion of the process?

Question 4

Consider the Round Robin scheduling algorithm with the time quantum of 2. There are 5 processes for which their process id, arrival time and burst time are given as:

Average waiting time and completion of execution of the processes?

Question 5

Convey effect is not observed in which of the following?

1.FCFS
2.SJF
3.SRTF

Question 6

Which of the following is true?

Question 7

Which among the following is correct in case of Spatial locality?

Question 8

In multithreading, which of the following statements is correct?

Question 9

Which of the following statements is correct when user-level threads are compared to Kernel-level threads?

Question 10

In indirect communication between Processes P and Q what do the two process have in common or what do they share

Question 11

The solution to the Critical Section problem includes mutual exclusion, progress and bounded waiting between two processes. To provide better synchronization between processes there is synchronization in hardware, then choose the false among the following in context to hardware?

Question 12

Solve the following code by co-begin and co-end
x=4;
co-begin
X= x+5
X= x+3
co-end
The final value of X will be

Question 13

Suppose n processes, P1, …. Pn share m identical resource units, which can be reserved and released one at a time. The maximum resource requirement of process Pi is Si, where Si > 0. Which one of the following is a sufficient condition for ensuring that deadlock does not occur?

Question 14

Which of the following is not a necessary condition(s) for a deadlock?

Question 15

Assume a system with 4 resources, C = (6, 4, 4,2). = The maximum claim table and the resource allocation tables are given below.

What happens if the resource allocator allocates 1 instance of R0 and 1 instance of R1 to the process P3 ?