Study desk with books and learning tools for subject-based MCQ preparation

Focused topic practice

field effect transistors fet MCQs

Practise focused field effect transistors fet questions with marked answers for exam preparation and subject revision.

field effect transistors fet Mcqs
1. In a JFET, IDSS is known as ________________?
comments icon0

A. none of the above

B. drain to source current

C. drain to source current with gate shorted

D. drain to source current with gate open

2. A JFET has high input impedance because _________________?
comments icon0

A. of impurity atoms

B. none of the above

C. it is made of semiconductor material

D. input is reverse biased
3. The constant-current region of a JFET lies between______________?
comments icon0
A. pinch-off and breakdown

B. cut off and saturation

C. cut off and pinch-off

D. and IDSS

4. A JFET is similar in operation to ___________ valve?
comments icon0

A. triode

B. tetrode

C. pentode

D. diode

5. The gate of a JFET is ___________ biased?
comments icon0

A. forward

B. reverse

C. none of the above

D. reverse as well as forward

6. A certain D-MOSFET is biased at VGS = 0 V. Its data sheet specifies IDSS = 20mA and VGS(off) = -5 V. The value of the drain current is _____________?
comments icon0
A. 20 mA

B. 0 mA

C. 40 mA

D. 10 mA

7. In a certain CS JFET amplifier, RD= 1kO , RS= 560 O , VDD=10V and gm= 4500 S. If the source resistor is completely bypassed, the voltage gain is ________________?
comments icon0

A. 2.52

B. 45

C. 450

D. 4.5

8. A certain JFET data sheet gives VGS(off) = -4 V. The pinch-off voltage Vp is _____________?
comments icon0

A. -4 V

B. data insufficient

C. +4 V

D. dependent on VGS

9. When drain voltage equals the pinch-off-voltage, then drain current ___________ with the increase in drain voltage?
comments icon0

A. decreases

B. increases

C. none of the above

D. remains constant
10. The two important advantages of a JFET are _________________?
comments icon0

A. inexpensive and high output impedance

B. none of the above

C. low input impedance and high output impedance

D. high input impedance and square-law property
11. In a p-channel JFET, the charge carriers are _____________?
comments icon0

A. electrons

B. holes

C. both electrons and holes

D. none of the above

12. _____________ has the lowest noise-level?
comments icon0

A. triode

B. tetrode

C. JFET

D. ordinary trnsistor

13. A MOSFET is sometimes called______________ JFET?
comments icon0

A. open gate

B. many gate

C. insulated gate

D. shorted gate

14. The pinch-off voltage of a JFET is about _______________?
comments icon0

A. 25 V

B. 0.6 V

C. 5 V

D. 15 V

15. A JFET is a__________ driven device?
comments icon0

A. current

B. voltage

C. both current and voltage

D. none of the above

16. A n-channel D-MOSFET with a positive VGS is operating in _______________?
comments icon0
A. the enhancement-mode

B. cut off

C. saturation

D. the depletion-mode

17. A MOSFET can be operated with________________?
comments icon0

A. negative gate voltage only

B. positive gate voltage only

C. none of the above

D. positive as well as negative gate voltage
18. A JFET is also called____________ transistor?
comments icon0

A. bipolar

B. unipolar

C. unijunction

D. none of the above

19. A JFET has three terminals, namely________________?
comments icon0

A. emitter, base, collector

B. none of the above

C. cathode, anode, grid

D. source, gate, drain
20. A MOSFET uses the electric field of a _______________to control the channel current?
comments icon0

A. battery

B. none of the above

C. generator

D. capacitor
21. n a common-source JFET amplifier, the output voltage is _____________?
comments icon0

A. taken at the source

B. in phase with the input

C. 180o out of phase with the input

D. 90o out of phase with the input

22. If load resistance in the above question (Q.49) is removed, the output voltage will_____________?
comments icon0
A. increase

B. stay the same

C. decrease

D. be zero

23. If the gate of a JFET is made less negative, the width of the conducting channel__________________?
comments icon0

A. remains the same

B. is increased

C. none of the above

D. is decreased

24. In a JFET, when drain voltage is equal to pinch-off voltage, the depletion layers ______________?
comments icon0

A. none of the above

B. have moderate gap

C. almost touch each other

D. have large gap

25. The input impedance of a MOSFET is of the order of______________?
comments icon0

A. kO

B. several MO

C. O

D. a few hundred O

26. In a FET, there are _____________pn junctions at the sides?
comments icon0

A. four

B. three

C. two

D. five

27. 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_______________?
comments icon0

A. 8.75

B. 11.4

C. 1

D. 3.2

28. A certain common-source JFET has a voltage gain of 10. If the source bypass capacitor is removed, ______________?
comments icon0

A. the voltage gain will increase

B. the Q-point will shift

C. the voltage gain will decrease

D. the transconductance will increase

29. The pinch-off voltage in a JFET is analogous to _____________ voltage in a vacuum tube?
comments icon0

A. none of the above

B. anode

C. cathode

D. grid cut off
30. A MOSFET has______________ terminals?
comments icon0
A. three

B. four

C. two

D. five

31. If the cross-sectional area of the channel in n-channel JEFT increases, the drain current _____________?
comments icon0

A. is decreased

B. remains the same

C. is increased

D. none of the above

32. A CS JFET amplifier has a load resistance of 10 kO , RD= 820O . If gm= 5mS and Vin= 500 mV, the output signal voltage is__________________?
comments icon0

A. 25 V

B. 1.89 V

C. 2.05 V

D. 0.5 V

33. Which of the following devices has the highest input impedance ?
comments icon0

A. ordinary transistor

B. Crystal diode

C. JFET

D. MOSFET
34. A JFET has ____________ power gain?
comments icon0

A. very small

B. small

C. very high

D. none of the above

35. The input control parameter of a JFET is __________________?
comments icon0

A. drain voltage

B. source voltage

C. gate voltage

D. gate current

36. The output characteristics of a JFET closely resemble the output characteristics of a ___________ valve?
comments icon0

A. tetrode

B. triode

C. diode

D. pentode
37. A MOSFET differs from a JFET mainly because _________________?
comments icon0

A. the MOSFET has two gates

B. none of the above

C. the JFET has a pn junction

D. of power rating

38. A certain p-channel E-MOSFET has VGS(th) = -2V. If VGS= 0V, the drain current is ____________?
comments icon0

A. ID(on)

B. IDSS

C. 0 mA

D. maximum

39. In class A operation, the input circuit of a JFET is ____________ biased?
comments icon0
A. reverse

B. forward

C. not

D. none of the above

40. The transconductance of a JFET ranges from ________________?
comments icon0

A. above 1000 mA/V

B. 100 to 500 mA/V

C. 0.5 to 30 mA/V

D. 500 to 1000 mA/V

41. The channel of a JFET is between the ________________?
comments icon0

A. input and output

B. gate and source

C. gate and drain

D. drain and source
42. The source terminal of a JEFT corresponds to _____________ of a vacuum tube?
comments icon0

A. grid

B. plate

C. cathode

D. none of the above

43. If the reverse bias on the gate of a JFET is increased, then width of the conducting channel ______________?
comments icon0
A. is decreased

B. none of the above

C. is increased

D. remains the same

44. The gate voltage in a JFET at which drain current becomes zero is called ______________ voltage?
comments icon0

A. cut-off

B. active

C. pinch-off

D. saturation

45. For VGS = 0 V, the drain current becomes constant when VDS exceeds ________________?
comments icon0

A. cut off

B. V

C. VDD

D. VP
46. A common base configuration of a pnp transistor is analogous to _____________?of a JFET
comments icon0
A. common gate configuration

B. common source configuration

C. common drain configuration

D. none of the above

47. At cut-off, the JFET channel is _____________?
comments icon0

A. at its widest point

B. completely closed by the depletion region

C. reverse baised

D. extremely narrow