Operating Systems Concepts Quiz Part 2

The first fit, best fit and worst fit are strategies to select a

• process from a queue to put in memory

• free hole from a set of available holes

• processor to run the next process

• all of the above

For a page size of 200 words, What is the page number and offset for a logical address of 1142

• 5, 142

• 2, 142

• 6, 142

• 7, 140

The process A, B, C. D and E references in the following order. A, B, C, D, A, B, E, A, B, C, D, E for the LRU page replacement algorithms with 4 frames. The number of page faults with pure demand paging is

• 6

• 7

• 8

• 9

Suppose that a disk drive has 5000 tracks, numbered from 0 to 4999. The drive is currently serving a request at track 143 and the previous was at track 125. The queue of pending requests in FIFO order is 86, 1470, 913, 1774, 984, 1509, 1022, 1750, 130 . Starting from the current position, the total distance in terms of track movement for SSTF is

• 640

• 246

• 350

• None

External fragmentation exists when ....... ?

• enough total memory exists to satisfy a request but it is not contiguous

• the total memory is insufficient to satisfy a request

• a request cannot be satisfied even when the total memory is free

• none of the mentioned

Which memory management technique allows for efficient utilization of memory by allocating memory in variable-sized blocks?

• Paging

• Segmentation

• Swapping

• Fragmentation

A memory management system has 64 pages with 512 bytes page size. Physical memory consists of 32 page frames Number of bits required in logical and physical address are respectively:

• 14 and 15

• 14 and 29

• 15 and 14

• 16 and 32

Consider the reference string: 0 1 2 3 0 1 4 0 1 2 3 4 If FIFO page replacement algorithm is used, then the number of page faults with three page frames and four page frames are ____ and ___ respectively.

• 10, 9

• 9, 9

• 10, 10

• 9, 10

Consider a disk queue with I/O requests on the following cylinders in their arriving order: 6,10,12,54,97,73,128,15,44,110,34,45. The disk head is assumed to be at cylinder 23 and moving in the direction of decreasing number of cylinders. Total number of cylinders in the disk is 150. The disk head movement using SCAN -scheduling algorithm is:

• 172

• 173

• 151

• 161

In the ..... algorithm, the disk head moves from one end to the other, servicing requests along the way. When the head reaches the other end, it immediately returns to the beginning of the disk without servicing any requests on the return trip.

• LOOK

• SCAN

• C-SCAN

• C-LOOK