1.
A
hierarchical memory system that uses cache memory has cache access time of 50
nano seconds, main memory access time of 300 nano seconds, 75% of memory
requests are for read, hit ratio of 0.8 for read access and the write-through
scheme is used. What will be the average access time of the system both for
read and write requests ?
(A) 157.5 n.sec. (B) 110 n.sec.
(C) 75 n.sec. (D) 82.5 n.sec.
Answer: A
Explanation:
The average access time
of the system for memory read cycle is
0.8x50+0.2x350=110ns
The average access time
of the system for both read and writes request is
0.75x110+0.25x300=82.5+75=157.5
2.
For
switching from a CPU user mode to the supervisor mode following type of
interrupt is most appropriate
(A) Internal interrupts (B) External interrupts
(C) Software interrupts (D) None of the above
Answer: C
3.
In a
dot matrix printer the time to print a character is 6 m.sec., time to space in
between characters is 2 m.sec., and the number of characters in a line are 200.
The printing speed of the dot matrix printer in characters per second and the
time to print a character line are given by which of the following options ?
(A) 125 chars/second and
0.8 seconds
(B) 250 chars/second and
0.6 seconds
(C) 166 chars/second and
0.8 seconds
(D) 250 chars/second and
0.4 seconds
Answer: A
Explanation:
Time to print a
character = 6+2=8 m.sec.
Number of characters in
a line = 200
Time to print a
character line = 200x8=1600 m.sec. = 1.6 seconds
Printing speed in
characters per second = 200/1.6 = 125 chars/second
4.
Match
the following 8085 instructions with the flags :
List –
I List – II
a. XCHG i. only carry flag is affected.
b. SUB ii. no flags are affected.
c. STC iii. all flags other than carry
flag are affected.
d. DCR iv. all flags are affected.
Codes
:
a b c
d
(A) iv i iii
ii
(B) iii ii i
iv
(C) ii iii i iv
(D) ii iv i
iii
Answer: D
5.
How
many times will the following loop be executed ?
LXI B, 0007 H
LOP : DCX B
MOV A, B
ORA C
JNZ LOP
(A) 05 (B) 07
(C) 09 (D) 00
Answer: B
6.
Specify
the contents of the accumulator and the status of the S, Z and CY flags when
8085 microprocessor performs addition of 87 H and 79 H.
(A) 11, 1, 1, 1 (B) 10, 0, 1, 0
(C) 01, 1, 0, 0 (D) 00, 0, 1, 1
Answer: D
7.
Location
transparency allows :
I. Users to treat the
data as if it is done at one location.
II. Programmers to treat
the data as if it is at one location.
III. Managers to treat
the data as if it is at one location.
Which one of the
following is correct ?
(A) I, II and III (B) I and II only
(C) II and III only (D) II only
Answer: A
8.
Which
of the following is correct ?
I. Two phase locking is
an optimistic protocol.
II. Two phase locking is
pessimistic protocol
III. Time stamping is an
optimistic protocol.
IV. Time stamping is
pessimistic protocol.
(A) I and III (B) II and IV
(C) I and IV (D) II and III
Answer: D
9.
...............
rules used to limit the volume of log information that has to be handled and processed
in the event of system failure involving the loss of volatile information.
(A) Write-ahead log (B) Check-pointing
(C) Log buffer (D) Thomas
Answer: B
10.
Let R
= ABCDE is a relational scheme with functional dependency set F = {A®B, B®C, AC®D}. The attribute closures of A and E are
(A) ABCD, f (B)
ABCD, E
(C) F, f (D) ABC, E
Answer: B
0 Comments