What is a depletion-mode field-effect transistor (FET)?
An FET that exhibits a current flow between source and drain when no gate voltage is applied✓Correct answer
An FET that has no current flow between source and drain when no gate voltage is applied
An FET that exhibits very high electron mobility due to a lack of holes in the N-type material
An FET for which holes are the majority carriers
Explanation
A depletion-mode FET is manufactured with a conducting channel already in place, so drain current flows with zero gate-to-source voltage and gate bias is used to pinch that channel off. The device that carries no current until gate voltage creates a channel is the enhancement-mode type; the other choices describe carrier mobility and carrier type rather than operating mode.