The ____ Amplifier has high input impedance, low output impedance, and low-voltage gain....

Question

a) Common-source,

b) common-gate,

c) common-drain

Answer 1

common drain, ie, a source follower has a gain less than 1. and a high input Z and low output Z.

.

Answer 2

This is a bit of a tricky one.  My first thought is that it would be c) common-drain, but the "low-voltage gain ...." part of the question bug's me.  The common-drain (follower-circuit) has high-input impedance and low output impedance, but it has negative voltage gain. Gain less than one, essentially zero voltage gain.  If the device has even a low voltage gain, suggest to me that it at least has some positive gain above unity.  I think the answer is a) Common-source, for the following reason: it meets all the stated conditions, and, FET amplifiers are not, in general, considered high voltage gain devices.

Just my thoughts on the matter.