7) Which of the following statements is FALSE regarding a bridge
A) Bridge is a layer 2 device
B) Bridge reduces collision domain
C) Bridge is used to connect two or more LAN segments
D) Bridge reduces broadcast domain
Answer : (D)

8) What is the availability of a software with the following reliability figures?
Mean Time Between Failure (MTBF) = 25 days
Mean Time To Repair (MTTR) = 6 hours
A) 1%
B) 24%
C) 99%
D) 99.009%
Answer : (B)

9) A channel has a bit rate of 4 kbps and one-way propagation delay of 20 ms. The channel uses stop and wait protocol. The transmission time of the acknowledgement frame is negligible. To get a channel efficiency of at least 50%, the minimum frame size should be
A) 80 bytes
B) 80 bits
C) 160 bytes
D) 160 bits
Answer : (D)

10) In a depth-first traversal of a graph G with n vertices, k edges are marked as tree edges. The number of connected components in G is
A) k
B) k+1
C) n-k-l
D) n-k
Answer : (C)

11) Which of the following statements is TRUE about CSMA/CD
A) IEEE 802.11 wireless LAN runs CSMA/CD protocol
B) Ethernet is not based on CSMA/CD protocol
C) CSMA/CD is not suitable for a high propagation delay network like satellite network
D) There is no contention in a CSMA/CD network
Answer : (C)

12) Which one of the following regular expressions is NOT equivalent to the regular expression (a + b + c)* ?
A) (a* + b* + c*)*
B) (a*b*c*)*
C) ((ab)* + c*)*
D) (a*b* + c*)*
Answer : (C)