Question

A receiver is operated at a temperature of 300 K. The transistor used in the receiver have an average output resistance of 1 k. The Johnson noise voltage for a receiver with a bandwidth of 200 kHz is

(a) 1.8 µV

(b) 8.4 µV

(c) 4.3 µV

(d) 12.6 µV

I have been asked this question in an online quiz.

The origin of the question is Noise in chapter EDC Overview of Electronic Devices & Circuits

Answer 1

Correct choice is (a) 1.8 µV

To explain: v^2 = 4kBTR where symbols have their usual meanings, hence v = 1.8 µV.