MCQOPTIONS
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MCQOPTIONS
This section includes 47 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.
| 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 |
| Answer» C. active | |
| 2. |
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 |
| Answer» B. is decreased | |
| 3. |
A certain p-channel E-MOSFET has VGS(th) = -2V. If VGS= 0V, the drain current is ____________? |
| A. | 0 mA |
| B. | ID(on) |
| C. | maximum |
| D. | IDSS |
| Answer» B. ID(on) | |
| 4. |
In a JFET, IDSS is known as ________________? |
| A. | drain to source current |
| B. | drain to source current with gate shorted |
| C. | drain to source current with gate open |
| D. | none of the above |
| Answer» C. drain to source current with gate open | |
| 5. |
A common base configuration of a pnp transistor is analogous to _____________? of a JFET |
| A. | common source configuration |
| B. | common drain configuration |
| C. | common gate configuration |
| D. | none of the above |
| Answer» D. none of the above | |
| 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 _____________? |
| A. | 20 mA |
| B. | 0 mA |
| C. | 40 mA |
| D. | 10 mA |
| Answer» B. 0 mA | |
| 7. |
In a certain CS JFET amplifier, RD= 1kO , RS= 560 O , VDD=10V and gm= 4500 µS. If the source resistor is completely bypassed, the voltage gain is ________________? |
| A. | 450 |
| B. | 45 |
| C. | 2.52 |
| D. | 4.5 |
| Answer» E. | |
| 8. |
_____________ has the lowest noise-level? |
| A. | triode |
| B. | ordinary trnsistor |
| C. | tetrode |
| D. | JFET |
| Answer» E. | |
| 9. |
The source terminal of a JEFT corresponds to _____________ of a vacuum tube? |
| A. | plate |
| B. | cathode |
| C. | grid |
| D. | none of the above |
| Answer» C. grid | |
| 10. |
At cut-off, the JFET channel is _____________? |
| A. | at its widest point |
| B. | completely closed by the depletion region |
| C. | extremely narrow |
| D. | reverse baised |
| Answer» C. extremely narrow | |
| 11. |
A certain JFET data sheet gives VGS(off) = -4 V. The pinch-off voltage Vp is _____________? |
| A. | +4 V |
| B. | -4 V |
| C. | dependent on VGS |
| D. | data insufficient |
| Answer» B. -4 V | |
| 12. |
Which of the following devices has the highest input impedance ? |
| A. | JFET |
| B. | MOSFET |
| C. | Crystal diode |
| D. | ordinary transistor |
| Answer» C. Crystal diode | |
| 13. |
A MOSFET uses the electric field of a _______________to control the channel current? |
| A. | capacitor |
| B. | battery |
| C. | generator |
| D. | none of the above |
| Answer» B. battery | |
| 14. |
In a JFET, when drain voltage is equal to pinch-off voltage, the depletion layers ______________? |
| A. | almost touch each other |
| B. | have large gap |
| C. | have moderate gap |
| D. | none of the above |
| Answer» B. have large gap | |
| 15. |
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 |
| Answer» C. of impurity atoms | |
| 16. |
The two important advantages of a JFET are _________________? |
| A. | high input impedance and square-law property |
| B. | inexpensive and high output impedance |
| C. | low input impedance and high output impedance |
| D. | none of the above |
| Answer» B. inexpensive and high output impedance | |
| 17. |
A JFET has ____________ power gain? |
| A. | small |
| B. | very high |
| C. | very small |
| D. | none of the above |
| Answer» C. very small | |
| 18. |
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 |
| Answer» B. is increased | |
| 19. |
The input impedance of a MOSFET is of the order of______________? |
| A. | O |
| B. | a few hundred O |
| C. | kO |
| D. | several MO |
| Answer» E. | |
| 20. |
The pinch-off voltage of a JFET is about _______________? |
| A. | 5 V |
| B. | 0.6 V |
| C. | 15 V |
| D. | 25 V |
| Answer» B. 0.6 V | |
| 21. |
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 |
| Answer» D. none of the above | |
| 22. |
The transconductance of a JFET ranges from ________________? |
| A. | 100 to 500 mA/V |
| B. | 500 to 1000 mA/V |
| C. | 0.5 to 30 mA/V |
| D. | above 1000 mA/V |
| Answer» D. above 1000 mA/V | |
| 23. |
A MOSFET is sometimes called______________ JFET? |
| A. | many gate |
| B. | open gate |
| C. | insulated gate |
| D. | shorted gate |
| Answer» D. shorted gate | |
| 24. |
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 |
| Answer» D. none of the above | |
| 25. |
In a FET, there are _____________pn junctions at the sides? |
| A. | three |
| B. | four |
| C. | five |
| D. | two |
| Answer» E. | |
| 26. |
n a common-source JFET amplifier, the output voltage is _____________? |
| A. | 180o out of phase with the input |
| B. | in phase with the input |
| C. | 90o out of phase with the input |
| D. | taken at the source |
| Answer» B. in phase with the input | |
| 27. |
For VGS = 0 V, the drain current becomes constant when VDS exceeds ________________? |
| A. | cut off |
| B. | VDD |
| C. | VP |
| D. | V |
| Answer» D. V | |
| 28. |
A MOSFET has______________ terminals? |
| A. | two |
| B. | five |
| C. | four |
| D. | three |
| Answer» E. | |
| 29. |
If load resistance in the above question (Q.49) is removed, the output voltage will_____________? |
| A. | increase |
| B. | decrease |
| C. | stay the same |
| D. | be zero |
| Answer» B. decrease | |
| 30. |
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__________________? |
| A. | 2.05 V |
| B. | 25 V |
| C. | 0.5 V |
| D. | 1.89 V |
| Answer» E. | |
| 31. |
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 |
| Answer» C. 8.75 | |
| 32. |
A certain common-source JFET has a voltage gain of 10. If the source bypass capacitor is removed, ______________? |
| A. | the voltage gain will increase |
| B. | the transconductance will increase |
| C. | the voltage gain will decrease |
| D. | the Q-point will shift |
| Answer» D. the Q-point will shift | |
| 33. |
A n-channel D-MOSFET with a positive VGS is operating in _______________? |
| A. | the depletion-mode |
| B. | the enhancement-mode |
| C. | cut off |
| D. | saturation |
| Answer» C. cut off | |
| 34. |
The channel of a JFET is between the ________________? |
| A. | gate and drain |
| B. | drain and source |
| C. | gate and source |
| D. | input and output |
| Answer» C. gate and source | |
| 35. |
A JFET is a__________ driven device? |
| A. | current |
| B. | voltage |
| C. | both current and voltage |
| D. | none of the above |
| Answer» C. both current and voltage | |
| 36. |
In class A operation, the input circuit of a JFET is ____________ biased? |
| A. | forward |
| B. | reverse |
| C. | not |
| D. | none of the above |
| Answer» C. not | |
| 37. |
The constant-current region of a JFET lies between______________? |
| A. | cut off and saturation |
| B. | cut off and pinch-off |
| C. | and IDSS |
| D. | pinch-off and breakdown |
| Answer» E. | |
| 38. |
The input control parameter of a JFET is __________________? |
| A. | gate voltage |
| B. | source voltage |
| C. | drain voltage |
| D. | gate current |
| Answer» B. source voltage | |
| 39. |
The pinch-off voltage in a JFET is analogous to _____________ voltage in a vacuum tube? |
| A. | anode |
| B. | cathode |
| C. | grid cut off |
| D. | none of the above |
| Answer» D. none of the above | |
| 40. |
The output characteristics of a JFET closely resemble the output characteristics of a ___________ valve? |
| A. | pentode |
| B. | tetrode |
| C. | triode |
| D. | diode |
| Answer» B. tetrode | |
| 41. |
In a p-channel JFET, the charge carriers are _____________? |
| A. | electrons |
| B. | holes |
| C. | both electrons and holes |
| D. | none of the above |
| Answer» C. both electrons and holes | |
| 42. |
A JFET is also called____________ transistor? |
| A. | unipolar |
| B. | bipolar |
| C. | unijunction |
| D. | none of the above |
| Answer» B. bipolar | |
| 43. |
A MOSFET can be operated with________________? |
| A. | negative gate voltage only |
| B. | positive gate voltage only |
| C. | positive as well as negative gate voltage |
| D. | none of the above |
| Answer» D. none of the above | |
| 44. |
A JFET has three terminals, namely________________? |
| A. | cathode, anode, grid |
| B. | emitter, base, collector |
| C. | source, gate, drain |
| D. | none of the above |
| Answer» D. none of the above | |
| 45. |
A JFET is similar in operation to ___________ valve? |
| A. | diode |
| B. | pentode |
| C. | triode |
| D. | tetrode |
| Answer» C. triode | |
| 46. |
The gate of a JFET is ___________ biased? |
| A. | reverse |
| B. | forward |
| C. | reverse as well as forward |
| D. | none of the above |
| Answer» B. forward | |
| 47. |
When drain voltage equals the pinch-off-voltage, then drain current ___________ with the increase in drain voltage? |
| A. | decreases |
| B. | increases |
| C. | remains constant |
| D. | none of the above |
| Answer» D. none of the above | |