Question

Compared to bipolar transistors, field effect transistors are NOT normally characterized by:
1. high input impedance
2. a reverse-biased PN junction
3. low input impedance
4. low power consumption

Answer 1

Correct Answer - Option 3 : low input impedance

The difference between FET and BJT is explained in the following table:

FET	BJT
Unipolar device: Uses only one type of charge carrier	Bipolar device: Uses both electron and hole
Voltage-controlled device: voltage between gate and source control the current through the device.	Current-controlled device: Base current control the amount of collector current
High input resistance	Input impedance less than FET
Slower in switching	Faster in switching

Hence, Option 3 is correct.