operating system set 3 Detailed Explanation And More Example

Question : 1

IR (Instruction register)

a) Contains the address of an instruction to be fetched.

b) Contains the instruction most recently fetched

c) Specifies memory addresses.

d) None of these.

Question : 2

Virtual memory is

a) simple to implement

b) used on all major commercial operating systems

c) less efficient in utilization of memory

d) useful when fast I/O devices are not available

Question : 3

The following is not an advantage of User Level Threads (ULT).

a) Thread switching does not requires kernel mode privileges because all of the thread management are within the user address space of a single process.

b) Here scheduling can be application specific.

c) ULT can be run an any operating system.

d) When ULT executes a system call, not only that thread blocked, but all of the threads within the process are blocked.

Question : 4

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 : 5

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 : 6

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.