Fet(field Effect Transistors)(Electrical Engineering ) Questions and answers for exam Preparation

Question 1. The gate voltage in a JFET at which drain current becomes zero is called ___________ voltage

saturation
pinch-off
active
cut-off

Explanation:-

Answer: Option B. -> pinch-off

Question 2. The constant-current region of a JFET lies between

cut off and saturation
cut off and pinch-off
o and IDSS
pinch-off and breakdown

Explanation:-

Answer: Option D. -> pinch-off and breakdown

Question 3. A MOSFET differs from a JFET mainly because ___________

of power rating
the MOSFET has two gates
the JFET has a pn junction
none of the above

Explanation:-

Answer: Option C. -> the JFET has a pn junction

Question 4. The output characteristics of a JFET closely resemble the output characteristics of a ___________ valve

pentode
tetrode
triode
diode

Explanation:-

Answer: Option A. -> pentode

Question 5. A JFET has high input impedance because ___________

it is made of semiconductor material
input is reverse biased
of impurity atoms
none of the above

Explanation:-

Answer: Option B. -> input is reverse biased

Question 6. ___________ has the lowest noise-level

triode
ordinary trnsistor
tetrode
JFET

Explanation:-

Answer: Option D. -> JFET

Question 7. The pinch-off voltage of a JFET is about ___________

5 V
0.6 V
15 V
25 V

Explanation:-

Answer: Option A. -> 5 V

Question 8. Which of the following devices has the highest input impedance?

JFET
MOSFET
Crystal diode
ordinary transistor

Explanation:-

Answer: Option B. -> MOSFET

Question 9. The transconductance of a JFET ranges from ___________

100 to 500 mA/V
500 to 1000 mA/V
0.5 to 30 mA/V
above 1000 mA/V

Explanation:-

Answer: Option C. -> 0.5 to 30 mA/V

Question 10. In a p-channel JFET, the charge carriers are ___________

electrons
holes
both electrons and holes
none of the above

Explanation:-

Answer: Option B. -> holes