Field Effect Transistor – FET MCQ

1. FET is a device which has

  1. high input impedance and is current-controlled
  2. low input impedance and is voltage-controlled
  3. high input impedance and is voltage-controlled
  4. low input impedance and is current-controlled
Answer
Answer. c

2. FET is a _________ controlled device.

  1. voltage
  2. current
  3. resistance
  4. impedance
Answer
Answer. a

3. Thermal runway is not possible in FET because as temperature of FET increases

  1. mobility increases
  2. mobility decreases
  3. drain current decreases
  4. trans-conductance increases
Answer
Answer. b

4. When a JFET is cut-off, the depletion layers are

  1. far apart
  2. close together
  3. touching
  4. conducting
Answer
Answer. c

5. The transconductance of a JFET is computed at constant VDS by

  1. ratio of change in ID to change of VGS
  2. ratio of change in VGS to change of ID
  3. product of change in VGS to change of ID
  4. ratio of change in VDS to change of ID
Answer
Answer. a

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

  1. saturation
  2. pinch-off
  3. active
  4. cut-off
Answer
Answer. b

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

  1. pentode
  2. tetrode
  3. triode
  4. diode
Answer
Answer. a

8. The constant-current region of a JFET lies between

  1. cut off and saturation
  2. cut off and pinch-off
  3. 0 and IDSS
  4. pinch-off and breakdown
Answer
Answer. d

9. A JFET has high input impedance because ___________

  1. it is made of semiconductor material
  2. input is reverse biased
  3. of impurity atoms
  4. none of the above
Answer
Answer. b

10. A MOSFET differs from a JFET mainly because ___________

  1. of power rating
  2. the MOSFET has two gates
  3. the JFET has a pn junction
  4. none of the above
Answer
Answer. c

11. The gain of an FET amplifier can be changed by changing

  1. fm
  2. gm
  3. Rd
  4. None of these
Answer
Answer. b

12. JFET in properly biased condition ats as a

  1. current controlled current source
  2. voltage controlled voltage source
  3. voltage controlled current source
  4. impedance controlled current source
Answer
Answer. c

13. The input resistance of a FET is of the order of

  1. 100 Ω
  2. 10 kΩ
  3. 1 MΩ
  4. 100 MΩ
Answer
Answer. d

14. FET is which type of device?

  1. 4 terminal voltage controlled device
  2. 3 terminal voltage controlled device
  3. 3 terminal current controlled device
  4. 2 terminal current controlled device
Answer
Answer. b

15. Which of the following statement is wrong about FET?

  1. high input impedance
  2. more temperature stable than BJT
  3. current-controlled
  4. voltage-controlled
Answer
Answer. c

16. In which mode the JFET can operate?

  1. depletion-mode only
  2. enhancement-mode only
  3. saturation mode only
  4. noise mode only
Answer
Answer. a

17. What is the order of the trans-conductance geometric mean of a JFET?

  1. 1 mS
  2. 1 S
  3. 100 S
  4. 1000 S
Answer
Answer. a

18. FETs are

  1. either unipolar or bipolar
  2. unipolar devices
  3. bipolar devices
  4. none of these
Answer
Answer. b

19. The most common semiconductor used for manufacturing of FET is

  1. Gallium Arsenide
  2. Indium Arsenide
  3. Indium Gallium Arsenide
  4. Silicon
Answer
Answer. d

20. In FET, the current flow is mainly due to

  1. majority carriers
  2. minority carriers
  3. both majority carriers and minority carriers
  4. none of these
Answer
Answer. a
Pages: 1 2