31. In
a paged memory management algorithm, the hit ratio is 70%. If it takes 30 nanoseconds
to search Translation Look-aside Buffer (TLB) and 100 nanoseconds (ns) to
access memory, the effective memory access time is
(A) 91 ns (B)
69 ns
(C) 200 ns (D)
160 ns
Answer: D
Explanation:
The percentage of times that a page number is
found in the associative registers is called the hit ratio. A 70% hit ratio
means that we find the desired page number in the associative registers 70% of
the time. If it takes 30 nanoseconds to search the associative registers, and
100 nanoseconds to access memory, then a mapped memory access takes 130
nanoseconds when the page number is in the associative registers. If we fail to
find the page number in the associative registers (30 nanoseconds), then we
must first access memory for the page table and frame number (100 nanoseconds),
and then access the desired byte in memory (100 nanoseconds), for a total of 230
nanoseconds.
Effective access time = 0.70 x 130 + .30 x
230 = 91 + 69= 160
32. Match
the following:
List-I List-II
a. Multilevel feedback queue i. Time-slicing
b. FCFS ii.
Criteria to move processes between queues
c. Shortest process next iii. Batch processing
d. Round Robin Scheduling iv. Exponential Smoothening
Codes:
a
b c d
(A) i iii ii iv
(B) iv iii ii
i
(C) iii i iv
i
(D) ii iii iv
i
Answer: D
33. Consider
a system with five processes P0 through P4 and three
resource types R1, R2 and R3. Resource type R1
has 10 instances, R2 has 5 instances and R3 has 7
instances. Suppose that at time T0, the following snapshot of the system
has been taken :
Assume that now the process P1
requests one additional instance of type R1 and two instances of
resource type R3. The state resulting after this allocation will be
(A) Ready State (B) Safe State
(C) Blocked State (D) Unsafe State
Answer: B
34. Match
the following:
List-I List-II
a. Contiguous Allocation i. This scheme supports very large file
sizes.
b. Linked allocation ii. This allocation technique supports only
sequential files.
c. Indexed allocation iii. Number of disks required to access file is
minimal.
d. Multi-level indexed iv. This technique suffers from maximum
wastage of space in storing pointers
Codes:
a
b c d
(A) iii iv ii
i
(B) iii ii iv
i
(C) i ii iv iii
(D) i iv ii
iii
Answer: B
35. Which
of the following out commands will output "onetwothree"?
(A) for val; do echo-n $val; done < one
two three
(B) for one two three; do echo-n-; done
(C) for n in one two three; do echo-n $n;
done
(D) for n in one two three {echo-n $n}
Answer: C
36. Merge
sort makes two recursive calls. Which statement is true after these two
recursive calls finish, but before the merge step?
(A) The array elements from a heap
(B) Elements in each half of the array are
sorted amongst themselves.
(C) Elements in the first half of the array
are less than or equal to elements in second half of the array
(D) All of the above
Answer: B
37. A
text is made up of the characters α, β, γ, δ and σ with the probability 0.12,
0.40, 0.15, 0.08 and 0.25 respectively. The optimal coding technique will have
the average length of
(A) 1.7 (B) 2.15
(C) 3.4 (D) 3.8
Answer: B
38. Searching
for an element in the hash table requires O(1) time for the ...............
time, whereas for direct addressing it holds for the ............. time.
(A) worst-case, average (B) worst-case, worst-case
(C) average, worst-case (D) best, average
Answer: C
39. An
algorithm is made up of 2 modules M1 and M2. If time
complexity of modules M1 and
M2 are h(n) and g(n) respectively, the time complexity of the
algorithm is
(A) min (h(n),g(n))
(B) max (h(n),g(n))
(C) h(n) + g(n)
(D) h(n) * g(n)
Answer: B
40. What
is the maximum number of parenthesis that will appear on the stack at any one
time for parenthesis expression given by
( ()
(()) (()) )
(A) 2 (B)
3
(C) 4 (D)
5
Answer: B
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