47) Which of the following measures the number of lost or garbled messages as a fraction of the total sent in the sampling period

48) Minimum number of bits required to represent all the symbols together is

49) A field in the Ethernet message packet is

50) If data rate of ring is 20 Mbps, signal propagation speed is 200 b/ms, then number of bits that can be placed on the channel of 200 km is

51) What signal-to-noise ratio is needed to put a T1 carrier on a T0-kHz line ?