66 + Mcqs in Two Page 1 McqOptions

1.	Typical levels of efficiency for solar cells range from ________ to ________.
A.	10%, 40%
B.	40%, 50%
C.	50%, 75%
D.	75%, 100%
Answer» B. 40%, 50%

Discussion

2.	In general, silicon ________.
A.	has a higher conversion efficiency
B.	has greater stability
C.	is less subject to fatigue
D.	All of the above
Answer» E.

Discussion

3.	LCDs have ________ power requirement than (as) LEDs.
A.	a lower
B.	a higher
C.	the same
D.	None of the above
Answer» B. a higher

Discussion

4.	________ is (are) the most widely used material(s) for solar cells.
A.	Selenium
B.	Silicon
C.	Both selenium and silicon
D.	Cadmium sulfide
Answer» D. Cadmium sulfide

Discussion

5.	LCDs are characteristically ________ LEDs.
A.	the same speed as
B.	much slower than
C.	faster than
D.	much faster than
Answer» C. faster than

Discussion

6.	A decrease in illumination ________ the resistance R of a photoconductive cell.
A.	decreases
B.	increases
C.	maintains
D.	None of the above
Answer» C. maintains

Discussion

7.	The response time for cadmium selenide (CdSe) is ________.
A.	100 ms
B.	50 ms
C.	25 ms
D.	10 ms
Answer» E.

Discussion

8.	Ge has a ________ dark current and a ________ level of reverse current than silicon.
A.	higher, lower
B.	higher, higher
C.	lower, higher
D.	lower, lower
Answer» C. lower, higher

Discussion

9.	In photodiodes, an increase in light intensity ________ the reverse current.
A.	increases
B.	decreases
C.	maintains
D.	None of the above
Answer» B. decreases

Discussion

10.	The wavelength is usually measured in ________.
A.	angstrom units
B.	micrometers
C.	both angstrom units and micrometers
D.	None of the above
Answer» D. None of the above

Discussion

11.	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
Answer» E.

Discussion

12.	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
Answer» E.

Discussion

13.	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
Answer» C. increases

Discussion

14.	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
Answer» D. series, series

Discussion

15.	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
Answer» E.

Discussion

16.	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
Answer» B. very large, very large

Discussion

17.	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
Answer» C. 25 V

Discussion

18.	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
Answer» D. decreases, increases

Discussion

19.	Varactor diodes are ________.
A.	semiconductor devices
B.	voltage-dependent
C.	variable capacitors
D.	All of the above
Answer» E.

Discussion

20.	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
Answer» C. 1/4

Discussion

21.	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
Answer» C. the same

Discussion

22.	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
Answer» D. None of the above

Discussion

23.	In both n-type and p-type silicon materials, the ________ is the majority carrier in a Schottky diode.
A.	hole
B.	electron
C.	proton
D.	neutron
Answer» C. proton

Discussion

24.	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
Answer» B. less, high

Discussion

25.	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
Answer» D. None of the above

Discussion

26.	What is the resistance of thermistors at room temperature (20ºC)?
A.	5 k
B.	1 k
C.	100
D.	1
Answer» B. 1 k

Discussion

27.	What is the resistance of thermistors at boiling temperature (100ºC)?
A.	5 k
B.	1 k
C.	100
D.	1
Answer» D. 1

Discussion

28.	What is the ratio IP / IV for gallium arsenide?
A.	1:1
B.	5:1
C.	10:1
D.	20:1
Answer» E.

Discussion

29.	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
Answer» B. A few microamperes to several amperes

Discussion

30.	What is the range of the varying capacitor CT in varactor diodes?
A.	0 pF to 5 pF
B.	2 pF to 10 pF
C.	2 F to 100 F
D.	2 pF to 100 pF
Answer» E.

Discussion

31.	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
Answer» F.

Discussion

32.	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
Answer» D. Milliamperes, amperes

Discussion

33.	The current capability of power diodes can be increased by placing two or more in series.
A.	True
B.	False
C.	-
D.	-
Answer» C. -

Discussion

34.	The PIV rating of power diodes can be increased by stacking the diodes in series.
A.	True
B.	False
C.	-
D.	-
Answer» B. False

Discussion

35.	What are the typical ranges of reverse-bias current levels I S for low-power and high-power Schottky diodes at room temperature?
A.	Picoamperes, nanoamperes
B.	Nanoamperes, microamperes
C.	Microamperes, milliamperes
D.	Milliamperes, amperes
Answer» D. Milliamperes, amperes

Discussion

36.	What is the response time of cadmium sulfide (CdS) in photoconductive cells?
A.	100 ms
B.	50 ms
C.	25 ms
D.	10 ms
Answer» B. 50 ms

Discussion

37.	What is the resistance of thermistors at room temperature (20ÂºC)?
A.	5 k
B.	1 k
C.	100
D.	1
Answer» B. 1 k

Discussion

38.	The tuning diode is a ________-dependent, variable ________.
A.	voltage, resistor
B.	current, capacitor
C.	voltage, capacitor
D.	current, inductor
Answer» D. current, inductor

Discussion

39.	What type of temperature coefficient do thermistors have?
A.	Positive
B.	Negative
C.	Either positive or negative
D.	None of the above
Answer» D. None of the above

Discussion

40.	Which of the following diodes has a negative-resistance region?
A.	Schottky
B.	Varactor
C.	Tunnel
D.	Power
Answer» D. Power

Discussion

41.	What is the response time of light-emitting diodes (LEDs)?
A.	Less than 100 ns
B.	50 ms
C.	100 ms to 300 ms
D.	400 ms
Answer» B. 50 ms

Discussion

42.	What is the ratio I P / I V for gallium arsenide?
A.	1:1
B.	5:1
C.	10:1
D.	20:1
Answer» E.

Discussion

43.	Which of the following materials is (are) used in the manufacturing of thermistors?
A.	Ge
B.	Si
C.	A mixture of oxides of cobalt, nickel, strontium, or manganese
D.	All of the above
Answer» E.

Discussion

44.	This is an approximate equivalent circuit for the ________ diode.
A.	Schottky
B.	varicap
C.	tunnel
D.	-
Answer» B. varicap

Discussion

45.	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
Answer» E.

Discussion

46.	What is the resistance of thermistors at boiling temperature (100ÂºC)?
A.	5 k
B.	1 k
C.	100
D.	1
Answer» D. 1

Discussion

47.	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
Answer» C. 75

Discussion

48.	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
Answer» E.

Discussion

49.	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
D.	-
Answer» D. -

Discussion

50.	What is the power density received from the sun at sea level?
A.	10 mW/cm 2
B.	100 mW/cm 2
C.	500 mW/cm 2
D.	1 W/cm 2
Answer» C. 500 mW/cm 2

Discussion

Explore topic-wise MCQs in Active Filter Circuits.

Typical levels of efficiency for solar cells range from ________ to ________.

In general, silicon ________.

LCDs have ________ power requirement than (as) LEDs.

________ is (are) the most widely used material(s) for solar cells.

LCDs are characteristically ________ LEDs.

A decrease in illumination ________ the resistance R of a photoconductive cell.

The response time for cadmium selenide (CdSe) is ________.

Ge has a ________ dark current and a ________ level of reverse current than silicon.

In photodiodes, an increase in light intensity ________ the reverse current.

The wavelength is usually measured in ________.

The negative-resistance region of tunnel diodes can be used in the design of ________.

The p-n junction of a tunnel diode is doped at a level from ________ to ________ times that of a typical semiconductor diode.

In the negative-resistance region of tunnel diodes, as the terminal voltage increases, the diode current ________.

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 ________.

The majority of power diodes are constructed using silicon because of its higher ________ rating(s).

In the reverse-bias region of varactor diodes, the resistance RR in parallel with the varying capacitor is ________ and the series resistance RS is ________.

The normal range of reverse-bias voltage VR for varactor diodes is limited to about ________.

In varactor diodes, as the reverse-bias potential increases, the width of the depletion region ________, which in turn ________ the transition capacitance.

Varactor diodes are ________.

The PIV of Schottky diodes is usually ________ that of a comparable p-n junction unit.

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.

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.

In both n-type and p-type silicon materials, the ________ is the majority carrier in a Schottky diode.

Schottky diode construction results in a ________ uniform junction region and a ________ level of ruggedness.

Schottky diodes have ________.

What is the resistance of thermistors at room temperature (20ºC)?

What is the resistance of thermistors at boiling temperature (100ºC)?

What is the ratio IP / IV for gallium arsenide?

What is the limit of peak current IP in tunnel diodes?

What is the range of the varying capacitor CT in varactor diodes?

What metal(s) is(are) used in the construction of Schottky diodes?

What are the typical ranges of reverse-bias current levels IS for low-power and high-power Schottky diodes at room temperature?

The current capability of power diodes can be increased by placing two or more in series.

The PIV rating of power diodes can be increased by stacking the diodes in series.

What are the typical ranges of reverse-bias current levels I S for low-power and high-power Schottky diodes at room temperature?

What is the response time of cadmium sulfide (CdS) in photoconductive cells?

What is the resistance of thermistors at room temperature (20ÂºC)?

The tuning diode is a ________-dependent, variable ________.

What type of temperature coefficient do thermistors have?

Which of the following diodes has a negative-resistance region?

What is the response time of light-emitting diodes (LEDs)?

What is the ratio I P / I V for gallium arsenide?

Which of the following materials is (are) used in the manufacturing of thermistors?

This is an approximate equivalent circuit for the ________ diode.

Which of the following areas is (are) applications of varactor diodes?

What is the resistance of thermistors at boiling temperature (100ÂºC)?

For a 50-A unit, the PIV of the Schottky is about ________ compared to 150 V for the p-n junction variety.

Which of the following metals is (are) used in the fabrication of Schottky diodes?

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.

What is the power density received from the sun at sea level?

Typical levels of efficiency for solar cells range from to .

Ge has a dark current and a level of reverse current than silicon.

The p-n junction of a tunnel diode is doped at a level from to times that of a typical semiconductor diode.

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 .

In the reverse-bias region of varactor diodes, the resistance RR in parallel with the varying capacitor is and the series resistance RS is .

In varactor diodes, as the reverse-bias potential increases, the width of the depletion region , which in turn the transition capacitance.

Schottky diode construction results in a uniform junction region and a level of ruggedness.

The tuning diode is a -dependent, variable .