Question

In a receiver the input signal is 100 V, while the internal noise at the input is 10 V. With amplification the output signal is 2 V, while the output noise is 0.4 V. The noise figure of receiver is

(a) 2

(b) 0.5

(c) 0.2

(d) None of the mentioned

I had been asked this question in an online quiz.

Enquiry is from Noise topic in section EDC Overview of Electronic Devices & Circuits

Answer 1

Right choice is (a) 2

For explanation: NF = (100/10)/(2/0.4) or 2.