Multiple Choice Questions and Answers
Question 1 : Virtual memory is
(a) Simple to implement
(b) Used by all major commercial O.S.
(c) Less efficient memory utilization
(d) None of the above
Answer : (b)
Question 2 : Under virtual memory
(a) A single program is processed by two or more CPUs
(b) Two or more programs are stored in memory
(c) Only active pages are stored in memory
(d) None of the above
Answer : (c)
Question 3 : Overlay is
(a) A system program
(b) A technique of allowing a program to be larger than the amount of memory allocated to it
(c) An O.S. itself
(d) None of the above
Answer : (b)
Question 4 : Very high paging activity is known as
(a) Demand Paging
(b) Demand Segmentation
(c) Thrashing
(d) None of the above
Answer : (c)
Question 5 : The process of temporarily removing inactive programs from the main memory of a computer system is known as
(a) Swapping
(b) Compaction
(c) Mapping
(d) None of the above
Answer : (a)
Question 6 : The effective access time (EAT) of demand paging is given by the formula
(a) EAT = (1-p) * mt + p * page fault time
(b) EAT = (1+p) * mt + p * page – fault time
(c) EAT = (1* p * mt ) + p * page – fault time
(d) None of the above
Answer : (a)
Question 7 : Page fault rate (PFR) is given by
(a) No. of page faults * No. of bits in the reference string
(b) No. of page faults/No. of bits in the reference string
(c) No. of page faults + No. of bits in the reference string
(d) None of the above
Answer : (b)
Question 8 : Replace a page that has not been used for the longest period of time is the criteria of which of these algorithms
(a) FIFO
(b) LRU
(c) Optimal
(d) None of the above
Answer : (b)
Question 9 : If the number of frames is increased, the page fault rate will decrease. This is known as
(a) Belady’s Anomaly
(b) Working Set Theory
(c) Thrashing
(d) None of the above
Answer : (a)
Question 10 : A high paging rate
(a) May cause high I/O rate
(b) Keeps the system well running
(c) Shows too much of processor activity
(d) None of the above
Answer : (a)
Question 11 : The page fault frequency in virtual memory is reduced when
(a) the page size is reduced
(b) Processes are unbound
(c) Locality of reference is applicable to the process
(d) None of the above
Answer : (c)
Question 12 : Loading the pages before letting processes run is known as
(a) Paging
(b) Pre-paging
(c) Thrashing
(d) Compaction
Answer : (b)
Question 13 : A reference bit (R) is used in which of the following algorithms
(a) Second chance page replacement algorithm
(b) Clock page replacement algorithm
(c) Both ‘a’ and ‘b’
(d) None of the above
Answer : (c)
Question 14 : One way to provide protection through hardware is
(a) Using databases
(b) Using Fence Register
(c) Using counters
(d) None of the above
Answer : (b)
Question 15 : The process of merging adjacent holes to form a single larger hole is called as
(a) Fragmentation
(b) Coalescing
(c) Swapping
(d) None of the above
Answer : (b)