Operating System MCQ’s With answers-Chapter 08

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Operating System MCQ’s with answer,  100% free MCQ PDF DOWNLOAD

141. In disk scheduling, the seek time is
(A) The time taken to position the head at the track.
(B) The time taken to reach the beginning of sector once the track is selected.
(C) A and B both.
(D) None of these.

142. The access time in disk scheduling is
(A) The time taken to position the head at the track.
(B) The time taken to reach the beginning of the sector of the track.
(C) The sum of seek time and rotational delay.
(D) None of these.

143. The transfer time in disk scheduling is
(A) Proportional to rotation speed.
(B) Inversely proportional to rotation speed.
(C) Equal to rotation speed.
(D) None of these.

144. 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.

145. 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.

146. RAID (Redundant Array of Independent Disks) scheme consists of
(A) Five levels from one to six.
(B) Six levels, from zero to five.
(C) Seven levels, from zero to six.
(D) None of these.

147. In RAID scheme, which of the RAID level does not use parity calculation in redundancy achievement
(A) RAID 4
(B) RAID 3
(C) RAID 2
(D) RAID 1

148. In system buffer cache, used in UNIX, following not true
(A) It is a disk cache
(B) It is not a disk cache
(C) Data transfer between buffer cache and user process space always occurs using DMA.
(D) I/O operations with disk are handled through buffer code.

149. In disk scheduling, the shortest service time first policy selects the disk request that
(A) In cure the maximum seek time
(B) In cure the minimum seek time
(C) Is received first
(D) Is received at last.

150. The C–SCAN, in disk scheduling states
(A) The arm movement is uni directional
(B) The arm movement is bidirectional
(C) The are is to be state fixed
(D) None of these.

151. RAID-O does not support the following characteristics:
A: RAID is a set of physical disk drives viewed by the operating system as a single logical drive.
B: Data distributed across the physical drives of an array.
C: Redemdant disk capacity is used to store parity information, which guarantees data recoverability in case of a disk failure.
(A) A and B
(B) A only
(C) B only
(D) C only

252. The UNIX scheduling gives
(A) Highest preference to real time processes
(B) Highest preference to kernel mode processes
(C) Highest preference to user mode processes
(D) Highest preference to shared processes.

153. In disk scheduling when SCAN (Look) policy is applied and when last track reached in one direction
(A) The service direction is reversed and scan proceeds in opposite direction.
(B) The arm returns to the opposite end of the disk and scan begins again.
(C) A and B both true.
(D) None of these.

154. In RAID (Redundant Array of Independent Disks) scheme, which of the following RAID level does not include redundancy to improve performance ?
(A) RAID level 0
(B) RAID level 1
(C) RAID level 2
(D) RAID level 4

155. In which of the following RAID scheme, redundancy is achieved by the simple expedient of duplicating all the data ?
(A) RAID level 0
(B) RAID level 1
(C) RAID level 2
(D) RAID level 3

156. In shortest service time first policy, applied on disk scheduling, the disk request is selected
(A) That requires the least movement of disk arm from its current position.
(B) That requires the maximum movement of disk arm from its current position.
(C) That is recently received.
(D) On random.

157. The RAID (Redundant Array of Independent Disks) level one requires
(A) Same disk space of the logical disk that it support.
(B) Twice disk space of the logical disk that it support.
(C) Thrice disk space of the logical disk that it support.
(D) Half disk space of the logical disk that it support.

158. Match the following in RAID scheme : AParallel access array, B-Independent access array,
1- All member disks participate in the execution of every I/O request.
2- Each member disk participates separately in the execution of every I/O request.
3- Here spindles of the individual drives are synchronized so that each disk head is in the same position on each disk at any given time.
(A) A – 1, 3 and B – 2
(B) A – 1, and B – 2, 3
(C) A – 2 and B – 1, 3
(D) A – 1, 2 and B – 3

159. The following RAID level employer parallel access technique and single redundant disk
(A) RAID level 0
(B) RAID level 1
(C) RAID level 2
(D) RAID level 3

160. The RAID scheme indicate
(A) Random access of information data.
(B) Random array of independent disks.
(C) Redundant array of independent disks.
(D) Redundant access of information data.


141. (A) 142. (C) 143. (A) 144. (B) 145. (A)
146. (C) 147. (D) 148. (B) 149. (B) 150. (C)
151. (D) 152. (A) 153. (A) 154. (A) 155. (B)
156. (A) 157. (B) 158. (A) 159. (D) 160. (D)