MCQOPTIONS
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MCQOPTIONS
This section includes 72 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
The transconductance of a JFET ranges from ___________$? |
| A. | 100 to 500 mA/V |
| B. | 500 to 1000 mA/V |
| C. | 0.5 to 30 mA/V |
| D. | above 1000 mA/V |
| Answer» D. above 1000 mA/V | |
| 52. |
A certain common source JFET has a voltage gain of 10. If the source bypass capacitor is removed, ___________$? |
| 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 | |
| 53. |
In a JFET, when drain voltage is equal to pinch-off voltage, the depletion layers$? |
| A. | almost touch each other |
| B. | have large gap |
| C. | have moderate gap |
| D. | none of the above |
| Answer» B. have large gap | |
| 54. |
If the cross-sectional area of the channel in n-channel JEFT increases, the drain current ___________$? |
| A. | is increased |
| B. | is decreased |
| C. | remains the same |
| D. | none of the above |
| Answer» B. is decreased | |
| 55. |
A MOSFET uses the electric field of a ___________ to control the channel current$? |
| A. | capacitor |
| B. | battery |
| C. | generator |
| D. | none of the above |
| Answer» B. battery | |
| 56. |
The output characteristics of a JFET closely resemble the output characteristics of a ___________ valve$? |
| A. | pentode |
| B. | tetrode |
| C. | triode |
| D. | diode |
| Answer» B. tetrode | |
| 57. |
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 | |
| 58. |
A JFET has ___________ power gain |
| A. | small |
| B. | very high |
| C. | very small |
| D. | none of the above |
| Answer» C. very small | |
| 59. |
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 | |
| 60. |
Which of the following devices has the highest input impedance? |
| A. | JFET |
| B. | MOSFET |
| C. | Crystal diode |
| D. | ordinary transistor |
| Answer» C. Crystal diode | |
| 61. |
The input impedance of a MOSFET is of the order of ___________ |
| A. | O |
| B. | a few hundred O |
| C. | kΩ |
| D. | several MO |
| Answer» E. | |
| 62. |
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 | |
| 63. |
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 | |
| 64. |
The input impedance of a JFET is ___________ that of an ordinary transistor |
| A. | equal to |
| B. | less than |
| C. | more than |
| D. | none of the above |
| Answer» D. none of the above | |
| 65. |
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 | |
| 66. |
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 | |
| 67. |
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 | |
| 68. |
___________ has the lowest noise-level |
| A. | triode |
| B. | ordinary trnsistor |
| C. | tetrode |
| D. | JFET |
| Answer» E. | |
| 69. |
In a FET, there are ___________ pn junctions at the sides |
| A. | three |
| B. | four |
| C. | five |
| D. | two |
| Answer» E. | |
| 70. |
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 | |
| 71. |
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 | |
| 72. |
The input control parameter of a JFET is ___________ |
| A. | gate voltage |
| B. | source voltage |
| C. | drain voltage |
| D. | gate current |
| Answer» B. source voltage | |