Question

With the potential difference between the source and the drain kept small (VDS is small), the MOSFET behaves as a resistance whose value varies __________ with the overdrive voltage

(a) Linearly

(b) Inversely

(c) Exponentially

(d) Logarithmically

I had been asked this question in an online interview.

Question is taken from MOSFETs Device Strucuture and Physical Operation in section MOS Field Effect Transistors (MOSFETs) of Electronic Devices & Circuits

Answer 1

Right option is (b) Inversely

Best explanation: For small VDS, resistance r is given by

R = 1 / ((μn Cox)(w/l)(VOV)).