E4C04 - Amateur Extra Class

E4C04 : What is the noise figure of a receiver?
A The ratio of atmospheric noise to phase noise
B The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
C The ratio in dB of the noise generated in the receiver to atmospheric noise
D The ratio in dB of the noise generated by the receiver to the theoretical minimum noise
Correct Answer: The ratio in dB of the noise generated by the receiver to the theoretical minimum noise