FET vs BJTMediumQuestion 20239
Question
Field effect transistors (FETs) are voltage-controlled devices because:
- AThey use current to control current
- BGate voltage controls drain current with no gate current flowingCorrect
- CThey operate at higher voltage
- DThey have no minority carriers
Correct answer
Gate voltage controls drain current with no gate current flowing
Explanation
In a MOSFET or JFET, the gate controls current via an electric field effect with essentially zero gate current (very high input impedance). BJTs are current-controlled (base current controls collector current). FETs have much higher input impedance → preferred in amplifiers and logic circuits.