operating system set 3 Detailed Explanation And More Example

Question : 1

In disk scheduling, SCAN algorithm states

a) The arm is required to move in one direction only.

b) The arm can be moved in any direction.

c) The arm is fixed.

d) None of these.

Question : 2

In last- in-first- out, disk scheduling policy

a) Recently received request is entertained at the last.

b) Recently received request is entertained first.

c) Requests are selected at random

d) None of these.

Question : 3

In uni-processor scheduling, if nonpreemptive policy is applied then

a) Once a process is in running state, it continues to execute until it terminates or block itself.

b) Currently running process can be interrupted and moved to ready state by the operating system.

c) The clock interrupt is generated at periodic intervals.

d) None of these.

Question : 4

Disaster recovery

a) is needed by every installation

b) is never needed

c) varies in degree between installations

d) requires off-site computer for immediate use

Question : 5

Access to moving head disks requires three periods of delay before information is brought into memory. The response that correctly lists the three time delays for the physical access of data in the order of the relative speed from the slowest to the fastest is

a) latency time, cache overhead time, seek time

b) transmission time, latency time, seek time

c) seek time, latency time, transmission time

d) cache overhead time, latency time, seek time

Question : 6

In a fixed head disk, the number of read/write head per track are

a) One

b) Two

c) Three

d) Four.