ANALOG ELECTRONICS 39 MOST IMPORTANT MCQ PDF FOR VIZAG MT AND BEL PE EXAM 2017

1. Which of the following is (are)
diodes?

  • A. Schottky
  • B. Varactor
  • C. Tunnel
  • D. All of the above
ANS- D. All of the above
2. Which of the following metals is
(are) used in the fabrication of Schottky diodes?
  • A. Molybdenum
  • B. Platinum
  • C. Tungsten
  • D. All of the above
ANS- D. All of the above
3. What are the typical ranges of
reverse-bias current levels IS for low-power and high-power Schottky
diodes at room temperature?
  • A. Picoamperes, nanoamperes
  • B. Nanoamperes, microamperes
  • C. Microamperes, milliamperes
  • D. Milliamperes, amperes
ANS- C. Microamperes, milliamperes
4. What is the voltage drop across
Schottky diodes?
  • A. 0 V to 0.2 V
  • B. 0.7 V to 0.8 V
  • C. 0.8 V to 1.0 V
  • D. 1.0 V to 1.5 V
ANS- A. 0 V to 0.2 V
5. What metal(s) is(are) used in the
construction of Schottky diodes?
  • A. Molybdenum
  • B. Platinum
  • C. Tungsten
  • D. Silicon
  • E. Any of the above
ANS- E. Any of the above
6. For a 50-A unit, the PIV of the
Schottky is about _____ compared to 150 V for the p-n junction variety.
  • A. 25
  • B 50
  • C. 75
  • D. 100
ANS- B 50
7. Schottky diodes are very
effective at frequencies approaching _____.
  • A. 20 GHz
  • B. 10 MHz
  • C. 100 MHz
  • D. 1 MHz
ANS- A. 20 GHz
8. This is an approximate equivalent
circuit for the _____ diode.

  • A. Schottky
  • B. varicap
  • C. tunnel
ANS- A. Schottky
9. What is the range of the varying
capacitor CT in varactor diodes?
  • A. 0 pF to 5 pF
  • B. 2 pF to 100 µF
  • C. 2 µF to 100 µF
  • D. 2 pF to 100 pF
ANS- D. 2 pF to 100 pF
10. Which of the following areas is
(are) applications of varactor diodes?
  • A. FM modulators
  • B. Automatic-frequency control devices
  • C. Adjustable bandpass filters
  • D. All of the above
ANS- D. All of the above
11. The tuning diode is a
_____-dependent, variable _____.
  • A. voltage, resistor
  • B. current, capacitor
  • C. voltage, capacitor
  • D. current, inductor
ANS- C. voltage, capacitor
12. This is an equivalent circuit
for the _____ diode.

  • A. Schottky
  • B. varicap
  • C. tunnel
ANS- B. varicap
13. The varicap diode has a
transition capacitance sensitive to the applied reverse-bias potential that is
a maximum at zero volts and decreases _____ with increasing reverse-bias
potentials.
  • A. logarithmically
  • B. parabolically
  • C. exponentially
ANS- C. exponentially
14. The majority of power diodes are
constructed using _____.
  • A. molybdenum
  • B. platinum
  • C. tungsten
  • D. silicon
ANS- D. silicon
15. The current capability of power
diodes can be increased by placing two or more in series.
  • A. True
  • B. False
ANS- B. False
16. The PIV rating of power diodes
can be increased by stacking the diodes in series.
  • A. True
  • B. False
ANS- A. True
17. Which of the following diodes
has a negative-resistance region?
  • A. Schottky
  • B. Varactor
  • C. Tunnel
  • D. Power
ANS- C. Tunnel
18. Which of the following
semiconductor materials is (are) used in the manufacturing of tunnel diodes?
  • A. Germanium
  • B. Gallium
  • C. Both germanium and gallium arsenide
  • D. Silicon
ANS- C. Both germanium and gallium
arsenide
19. What is the ratio IP
/ IV for gallium arsenide?
  • A. 1:1
  • B. 5:1
  • C. 10:1
  • D. 20:1
ANS- D. 20:1
20. What is the limit of peak
current IP in tunnel diodes?
  • A. A few microamperes to several hundred amperes
  • B. A few microamperes to several amperes
  • C. A few microamperes to several milliamperes
  • D. A few microamperes to several hundred microamperes
ANS- A. A few microamperes to
several hundred amperes
21. What is the maximum peak voltage
for tunnel diodes?
  • A. 50 mV
  • B. 100 mV
  • C. 250 mV
  • D. 600 mV
ANS- D. 600 mV
22. In which region is the operating
point stable in tunnel diodes?
  • A. Negative-resistance
  • B. Positive-resistance
  • C. Both negative- and positive-resistance
  • D. Neither negative- nor positive-resistance
ANS- B. Positive-resistance
23. Which of the following diodes is
limited to the reverse-bias region in its region of operation?
  • A. Schottky
  • B. Tunnel
  • C. Photodiode
  • D. Rectifier
ANS- C. Photodiode
24. Schottky diodes have _____.
  • A. quick response time
  • B. a lower noise figure
  • C. both quick response time and a lower noise figure
  • D. None of the above
ANS-. C. both quick response time
and a lower noise figure
25. Schottky diode construction
results in a _____ uniform junction region and a _____ level of ruggedness.
  • A. more, high
  • B. less, high
  • C. more, low
  • D. less, low
ANS- A. more, high
26. In both n-type and p-type
silicon materials, the _____ is the majority carrier in a Schottky diode.
  • A. hole
  • B. electron
  • C. proton
  • C. neutron
ANS- B. electron
27. The barrier at the junction for
a Schottky diode is _____ that of the p-n junction device in both the forward-
and reverse-bias regions.
  • A. the same as
  • B. more than
  • C. less than
  • D. None of the above
ANS- C. less than
28. A Schottky diode has _____ level
of current at the same applied bias compared to that of the p-n junction at
both the forward- and reverse-bias regions.
  • A. a lower
  • B. a higher
  • C. the same
  • D. None of the above
ANS- B. a higher
29. The PIV of Schottky diodes is
usually _____ that of a comparable p-n junction unit.
  • A. 1/2
  • B. 1/3
  • C. 1/4
  • D. 1/5
ANS- B. 1/3
30. Varactor diodes are _____.
  • A. semiconductor devices
  • B. voltage-dependent
  • C. variable capacitors
  • D. All of the above
ANS- D. All of the above
31. In varactor diodes, as the
reverse-bias potential increases, the width of the depletion region _____,
which in turn _____ the transition capacitance.
  • A. increases, increases
  • B. decreases, reduces
  • C. increases, reduces
  • D. decreases, increases
ANS-. C. increases, reduces
32. The normal range of reverse-bias
voltage VR for varactor diodes is limited to about _____.
  • A. 15 V
  • B. 20 V
  • C. 25 V
  • D. 40 V
ANS- B. 20 V
33. In the reverse-bias region of
varactor diodes, the resistance RR in parallel with the varying
capacitor is _____ and the series resistance RS is _____.
  • A. very large, very small
  • B. very large, very large
  • C. very small, very large
  • D. very small, very small
ANS- A. very large, very small
34. The majority of power diodes are
constructed using silicon because of its higher _____ rating(s).
  • A. current
  • B. temperature
  • C. PIV
  • D. All of the above
ANS- D. All of the above
35. The current capability of power
diodes can be increased by placing two or more of the diodes in _____, and the
PIV rating can be increased by stacking the diodes in _____.
  • A. parallel, parallel
  • B. series, parallel
  • C. parallel, series
  • D. series, series
ANS- C. parallel, series
36. In the negative-resistance
region of tunnel diodes, as the terminal voltage increases, the diode current
_____.
  • A. remains the same
  • B. decreases
  • C. increases
  • D. is undefined
ANS- B. decreases
37. The p-n junction of a tunnel
diode is doped at a level from _____ to _____ times that of a typical
semiconductor diode.
  • A. one, several
  • B. several, ten
  • C. more than ten, several hundred
  • D. one hundred, several thousand
ANS- D. one hundred, several
thousand
38. The negative-resistance region
of tunnel diodes can be used in the design of _____.
  • A. oscillators
  • B. switching networks
  • C. pulse generators
  • D. All of the above
ANS- D. All of the above
39. The wavelength is usually
measured in _____.
  • A. angstrom units
  • B. micrometers
  • C. both angstrom units and micrometers
  • D. None of the above
ANS- C. both angstrom units and
micrometers
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DIGITAL ELECTRONICS 100 IMPORTANT MCQ PDF WITH SOLUTION FOR VIZAG MT AND BEL PE EXAM 2017

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