11) Null modems are a type of
a) Modem eliminator
b) Modem
c) Multiplexer
d) Protocol converter
12) Which one of the following is not a class of LAN?
a) Broad band
b) CSMAICD
c) Token bus
d) Token ring
13) CSMA/CD
a) is an important protocol
b) is IEEE 802.3 (Ethernet)
c) bothe a and b
d) none of the above
14) The amount of uncertainty in a system of symbol is called
a) Bandwidth
b) Entropy
c) Loss
d) Quantum
15) A bridge can-
a) filter a frame
b) forward a frame
c) extend a LAN
d) all of the above
16) HDLC is
a) bit-oriented
b) code dependent
c) both a and b
d) none of the above
17) Non-polling system is
a) TDMA’
b) stop and wait
c) continuous ARQ
d) none of these
18) DNS is used to locate the-
a) MAC address of URL
b) IP address of URL
c) Root domain of URL
d) Domain name of a URL
19) The topology with highest reliability is
a) bus topology
b) star topology
c) ring topology’
d) mesh topology
20) Which of the following items is not used in local area network (LAN)?
a) Computer
b) Modem
c) Printer
d) Cable