Noise in communication system
Q16. Noise is added to a signal in a communication system
a) At the receiving end
b) At transmitting antenna
c) In the channel
d) During regeneration of the information
Correct Answer: c) In the channel
Explanation: Noise is an unwanted electrical signal that is added with the transmitted signal while passing through the communication channel. The noise interferes with the signal and may produce distortions to the signal.
Q17. Noise power at the resistor is affected by the value of the resistor as
a) Directly proportional to the value of the resistor
b) Inversely proportional to the value of the resistor
c) Unaffected by the value of the resistor
d) Becomes half as the resistance value is doubled
Correct Answer: c) Unaffected by the value of the resistor
The Noise power is given by
K = 1.381×10-23 J/K, joules per Kelvin, the Boltzmann constant
B is the bandwidth at which the power Pn is delivered.
T noise temperature,
which is unaffected by change in the value of the resistor.