71) A terminal multiplexer has six 1200 bps terminals and (rf 300 bps terminals connected to it. The outgoing line is 9600 bps. What is the maximum value of n

72) Data link layer retransmits the damaged frames in most networks. If probability of a frame's being damaged is p, then what is the mean number of transmissions required to send a frame if acknowledgements are never lost ?

73) If a designer wants to design a point-to-point sub-network with 10 routers of full duplex line, then total number of lines among them would be

74) Maximum data rate of a noiseless 4 kHz channel using T1 PCM system is

75) Phase shift keying (PSK.) method is used to modulate digital signals at 9600 bps using 16 levels. The line signals speed (i.e. modulation rate) will be