51.
An operating system supports a paged virtual
memory, using a central processor with a cycle time of one microsecond. It
costs an additional one microsecond to access a page other than the current
one. Pages have 1000 words, and the paging device is a drum that rotates at
3000 revolutions per minute and transfers one million words per second. Further,
one percent of all instructions executed accessed a page other than the current
page. The instruction that accessed another page, 80% accessed a page already
in memory and when a new page was required, the replaced page was modified 50%
of the time. What is the effective access time on this system, assuming that
the system is running only one process and the processor is idle during drum
transfers ?
(A) 30 microseconds (B) 34 microseconds
(C) 60 microseconds (D) 68 microseconds
Answer: B
52.
Consider the following page reference string
:
1, 2, 3, 4, 2, 1, 5, 6, 2, 1, 2, 3, 7, 6, 3,
2, 1, 2, 3, 6
Which of the following options, gives the
correct number of page faults related to LRU, FIFO, and optimal page
replacement algorithms respectively, assuming 05 page frames and all frames are
initially empty ?
(A) 10, 14, 8 (B) 8, 10, 7
(C) 7, 10, 8 (D)
7, 10, 7
Answer: B
53.
Consider a file currently consisting of 50
blocks. Assume that the file control block and the index block is already in
memory. If a block is added at the end (and the block information to be added
is stored in memory), then how many disk I/O operations are required for
indexed (single-level) allocation strategy ?
(A) 1 (B)
101
(C) 27 (D)
0
Answer: A
54.
An experimental file server is up 75% of the
time and down for 25% of the time due to bugs. How many times does this file
server have to be replicated to give an availability of at least 99% ?
(A) 2 (B)
4
(C) 8 (D)
16
Answer: B
55.
Given the following two languages:
L1 = {uwwRn | u, v, w ϵ
{a, b}+}
L2 = {uwwRn | u, v, w ϵ
{a, b}+, |u| ≥ |v|}
Which of the following is correct ?
(A) L1 is regular language and L2
is not regular language.
(B) L1 is not regular language and
L2 is regular language.
(C) Both L1 and L2 are
regular languages.
(D) Both L1 and L2 are
not regular languages.
Answer: A
56.
Given a Turing Machine
M = ({q0, q1}, {0, 1},
{0, 1, B}, δ, B, {q1})
Where δ is a transition function defined as
δ (q0, 0) = (q0, 0, R)
δ (q0, B) = (q1, B, R)
The language L(M) accepted by Turing machine
is given as :
(A) 0* 1* (B)
00*
(C) 10* (D)
1*0*
Answer: B
57.
Let G = (V, T, S, P) be a context-free
grammar such that every one of its productions is of the form A → n, with |v| =
k > 1. The derivation tree for any string W ϵ L (G) has a height such that
Answer: D
58.
Which of the following is not used in standard
JPEG image compression?
(A) Huffman coding (B) Runlength encoding
(C) Zig-zag scan (D) K-L Transform
Answer: D
59.
Which of the following is a source coding
technique?
(A) Huffman coding (B) Arithmetic coding
(C) Run-length coding (D) DPCM
Answer: D
60.
If the histogram of an image is clustered
towards origin on X-axis of a histogram plot then it indicates that the image
is .............
(A) Dark (B)
Good contrast
(C) Bright (D)
Very low contrast
Answer: A
 - Part 6){kind=link}
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