Monday, 9 October 2017

UGC Net Computer Science December 13 Paper 3 Page 5 Solved



40.  Pumping lemma for context-free languages states : Let L be an infinite context free language. Then there exists some positive integer m such that any w ∈ L with |w| ≥ m can be decomposed as
w = uv xy Z with |vxy| _________ and |vy| _________ such that 
Z ∈ L for all .z = 0, 1, 2, ....... .
(A) ≤ m, ≤ 1
 (B) ≤ m, ≥ 1
(C) ≥ m, ≤ 1
(D) ≥ m, ≥ 1



41. The Greibach normal form grammar for the language L = {an bn + 1 | n ≥ 0} is
(A) S → a SB, B → bB | λ
(B) S → a SB, B → bB | b
(C) S → a SB | b, B → b
(D) S → a Sb | b

42. Given the following statements :
S1 : Every context-sensitive language L is recursive.
S2 : There exists a recursive language that is not context sensitive.
Which statement is correct ?
(A) S1 is not correct and S2 is not correct.
(B) S1 is not correct and S2 is correct.
(C) S1 is correct and S2 is not correct.
(D) S1 is correct and S2 is correct.


43. What is the bit rate for transmitting uncompressed 800 × 600 pixel colour frames with 8 bits/pixel at 40 frames/second ?
(A) 2.4 Mbps
(B) 15.36 Mbps
(C) 153.6 Mbps
(D) 1536 Mbps

44. In IPV 4, the IP address 200.200.200.200 belongs to
(A) Class A
(B) Class B
(C) Class C
(D) Class D

45. Which layer of OSI reference model is responsible for decomposition of messages and generation of sequence numbers to ensure correct re-composition from end to end of the network ?
(A) Physical
(B) Data-link
(C) Transport
 (D) Application

46.A client-server system uses a satellite network, with the satellite at a height of 40,000 kms. What is the best-case delay in response to a request ? (Note that the speed of light in air is 3,00,000 km/second).
(A) 133.33 m sec
(B) 266.67 m sec
(C) 400.00 m sec
(D) 533.33 m sec

47. The start and stop bits are used in serial communication for  (A) error detection
(B) error correction
(C) synchronization
(D) slowing down the communication

48. _________ is a type of transmission impairment in which the signal looses strength due to the resistance of the transmission medium.
(A) Attenuation
(B) Distortion
(C) Noise
(D) Decibel

49. Match the following :

List-I
List-II
a. Indexed
Addressing
i. is not used when an
operand is moved
from memory into a
register or from a
register to memory.
b. Direct
Addressing
ii. Memory address is
computed by
adding up two
registers plus an
(optional) offset.
c. Register
Addressing
iii. Addressing
memory by giving
a register plus a
content offset.
d. Base-
Indexed
Addressing
iv. can only be used to
access global
variables whose
address is known
at compile time.

Codes :
       a b c d
(A) ii i iv iii
(B) ii iv i iii
(C) iii iv i ii
(D) iii i iv ii

50. Which of the following is a design criteria for instruction formats ?
(A) The size of instructions
(B) The number of bits in the address fields
(C) The sufficient space in the instruction format to express all the operations desired.
(D) All of these