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This section includes 78 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. |
_ A crystal diode has$? |
A. | one pn junction |
B. | two pn junctions |
C. | three pn junctions |
D. | none of the above |
Answer» B. two pn junctions | |
52. |
_ The ratio of reverse resistance and forward resistance of a germanium crystal diode is about ___________$? |
A. | 1 : 1 |
B. | 100 : 1 |
C. | 1000 : 1 |
D. | 40000 : 1 |
Answer» E. | |
53. |
_ Mains a.c. power is converrted into d.c. power for ___________$? |
A. | lighting purposes |
B. | heaters |
C. | using in electronic equipment |
D. | none of the above |
Answer» D. none of the above | |
54. |
_ When the graph between current through and voltage across a device is a straight line, the device is referred to as ___________$? |
A. | linear |
B. | active |
C. | nonlinear |
D. | passive |
Answer» B. active | |
55. |
_ The most widely used rectifier is ___________$? |
A. | half-wave rectifier |
B. | centre-tap full-wave rectifier |
C. | bridge full-wave rectifier |
D. | none of the above |
Answer» D. none of the above | |
56. |
_ ___________ rectifier has the lowest forward resistance$? |
A. | solid state |
B. | vacuum tube |
C. | gas tube |
D. | none of the above |
Answer» B. vacuum tube | |
57. |
_ If the temperature of a crystal diode increases, then leakage current ___________$? |
A. | remains the same |
B. | decreases |
C. | increases |
D. | becomes zero |
Answer» D. becomes zero | |
58. |
_A crystal diode is a ___________ device$? |
A. | non-linear |
B. | bilateral |
C. | linear |
D. | none of the above |
Answer» B. bilateral | |
59. |
_The forward voltage drop across a silicon diode is about ___________$? |
A. | 2.5 V |
B. | 3 V |
C. | 10 V |
D. | 0.7 V |
Answer» E. | |
60. |
_The reverse current in a diode is of the order of ___________$? |
A. | kA |
B. | mA |
C. | μA |
D. | A |
Answer» D. A | |
61. |
_The PIV rating of each diode in a bridge rectifier is ___________ that of the equivalent centre-tap rectifier$? |
A. | one-half |
B. | the same as |
C. | twice |
D. | four times |
Answer» B. the same as | |
62. |
_The maximum efficiency of a half-wave rectifier is ___________$? |
A. | 40.6% |
B. | 81.2% |
C. | 50% |
D. | 25% |
Answer» B. 81.2% | |
63. |
_A zener diode utilizes ___________ characteristics for its operation.$? |
A. | forward |
B. | reverse |
C. | both forward and reverse |
D. | none of the above |
Answer» C. both forward and reverse | |
64. |
_When the crystal current diode current is large, the bias is ___________$? |
A. | forward |
B. | inverse |
C. | poor |
D. | reverse |
Answer» B. inverse | |
65. |
A zener diode is always ___________ connected.? |
A. | reverse |
B. | forward |
C. | either reverse or forward |
D. | none of the above |
Answer» B. forward | |
66. |
A series resistance is connected in the zener circuit to___________? |
A. | properly reverse bias the zener |
B. | protect the zener |
C. | properly forward bias the zener |
D. | none of the above |
Answer» C. properly forward bias the zener | |
67. |
A crystal diode has forward resistance of the order of ___________? |
A. | kΩ |
B. | Ω |
C. | MΩ |
D. | none of the above |
Answer» C. M≈í¬© | |
68. |
When a crystal diode is used as a rectifier, the most important consideration is ___________? |
A. | forward characteristic |
B. | doping level |
C. | reverse characteristic |
D. | PIC rating |
Answer» E. | |
69. |
The ripple factor of a half-wave rectifier is ___________? |
A. | 2 |
B. | 1.21 |
C. | 2.5 |
D. | 0.48 |
Answer» E. | |
70. |
The leakage current in a crystal diode is due to ___________? |
A. | minority carriers |
B. | majority carriers |
C. | junction capacitance |
D. | none of the above |
Answer» B. majority carriers | |
71. |
In the breakdown region, a zener didoe behaves like a ___________ source. |
A. | constant voltage |
B. | constant current |
C. | constant resistance |
D. | none of the above |
Answer» B. constant current | |
72. |
A zener diode has ___________ breakdown voltage |
A. | undefined |
B. | sharp |
C. | zero |
D. | none of the above |
Answer» C. zero | |
73. |
If the doping level in a crystal diode is increased, the width of depletion layer___________ |
A. | remains the same |
B. | is decreased |
C. | in increased |
D. | none of the above |
Answer» D. none of the above | |
74. |
If the doping level of a crystal diode is increased, the breakdown voltage___________ |
A. | remains the same |
B. | is increased |
C. | is decreased |
D. | none of the above |
Answer» D. none of the above | |
75. |
If the a.c. input to a half-wave rectifier is an r.m.s value of 400/‚Äö√ √∂2 volts, then diode PIV rating is ___________# |
A. | 400/‚Äö√ √∂2 V |
B. | 400 V |
C. | 400 x ‚Äö√ √∂2 V |
D. | none of the above |
Answer» C. 400 x ‚Äö√ √∂2 V | |
76. |
A crystal diode utilises ___________ characteristic for rectification |
A. | reverse |
B. | forward |
C. | forward or reverse |
D. | none of the above |
Answer» C. forward or reverse | |
77. |
A zener diode is ___________ device |
A. | a non-linear |
B. | a linear |
C. | an amplifying |
D. | none of the above |
Answer» B. a linear | |
78. |
If the arrow of crystal diode symbol is positive w.r.t. bar, then diode is ___________ biased. |
A. | forward |
B. | reverse |
C. | either forward or reverse |
D. | none of the above |
Answer» B. reverse | |