FET(Field Effect Transistors) MCQ Questions & Answers

1

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

A) saturation B) pinch-off C) active D) cut-off

Discuss

Answer & Solution

Answer: Option D

Solution:

The gate voltage in a JFET at which the drain current becomes zero is called the cut-off voltage.

Cut-off voltage is the gate-source voltage (V_GS) at which the JFET channel is completely pinched off, and the drain current (I_D) ceases.

At this point, the JFET is in the off state, and no current flows from drain to source.

Other terms like saturation, pinch-off, and active refer to different operating regions of the JFET, not the voltage at which the drain current is zero.

2

The output characteristics of a JFET closely resemble the output characteristics of a ___________ valve

A) pentode B) tetrode C) triode D) diode

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

3

The constant-current region of a JFET lies between

A) cut off and saturation B) cut off and pinch-off C) o and IDSS D) pinch-off and breakdown

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

4

A JFET has high input impedance because ___________

A) it is made of semiconductor material B) input is reverse biased C) of impurity atoms D) none of the above

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

5

A MOSFET differs from a JFET mainly because ___________

A) of power rating B) the MOSFET has two gates C) the JFET has a pn junction D) none of the above

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

6

If the reverse bias on the gate of a JFET is increased, then width of the conducting channel ___________

A) is decreased B) is increased C) remains the same D) none of the above

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

7

If the gate of a JFET is made less negative, the width of the conducting channel ___________

A) remains the same B) is decreased C) is increased D) none of the above

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

8

If the cross-sectional area of the channel in n-channel JEFT increases, the drain current ___________

A) is increased B) is decreased C) remains the same D) none of the above

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

9

In a certain common source D-MOSFET amplifier, Vds =3.2 V r.m. and Vgs = 280 mV r.m.s. The voltage gain is ___________

A) 1 B) 11.4 C) 8.75 D) 3.2

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

10

In a certain CS JFET amplifier, R_D = 1 kΩ , R_S = 560 Ω , V_DD = 10 V and g_m = 4500 µS. If the source resistor is completely bypassed, the voltage gain is ___________.

A) 450 B) 45 C) 2.52 D) 4.5

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

FET(Field Effect Transistors) MCQ Questions & Answers | Electrical Engineering