Question

If V1 is the voltage at port 1 and V2 is the voltage at port 2, then the attenuation in dB is?

(a) 20 log10 (V1/V2)

(b) 10 log10 (V1/V2)

(c) 20 log10 (V2/V1)

(d) 10 log10 (V2/V1)

This question was posed to me in homework.

Question is taken from Attenuators topic in section Filters and Attenuators of Network Theory

Answer 1

The correct choice is (a) 20 log10 (V1/V2)

For explanation I would say: If V1 is the voltage at port 1 and V2 is the voltage at port 2, then the attenuation in dB is Attenuation in dB = 20 log10 (V1/V2) where V1 is the voltage at port 1 and V2 is the voltage at port 2.