Special-Purpose Diodes

Special-Purpose Diodes

numberonestar Science

Special-Purpose Diodes

Schottky diodes
Schottky diodes

1. Schottky diodes are also known as
A. PIN diodes.
B. hot carrier diodes.
C. step-recovery diodes.
D. tunnel diodes.
Answer: Option B

2. Zener diodes with breakdown voltages less than 5 V operate predominantly in what type of breakdown?
A. avalanche
B. zener
C. varactor
D. Schottky
Answer: Option B

3. The Schottky diode is used
A. in high-power circuits.
B. in circuits requiring negative resistance.
C. in very fast-switching circuits.
D. in power supply rectifiers.
Answer: Option C

4. You have an application for a diode to be used in a tuning circuit. A type of diode to use might be
A. an LED.
B. a Schottky diode.
C. a Gunn diode.
D. a varactor.
Answer: Option D

5. Refer to this figure. Which symbol is correct for an LED?
diodes symbol
A. a
B. b
C. c
D. d
E. e
Answer: Option A

6. Refer to this figure If VIN increases, IZ will
zener diodes
A. increase.
B. decrease.
C. remain the same.
Answer: Option A

7. What kind of diode is formed by joining a doped semiconductor region with a metal?
A. laser
B. tunnel
C. pin
D. Schottky
Answer: Option D

8. Refer to this figure. Which symbol is correct for a zener diode?
diodes symbol
A. a
B. b
C. c
D. d
E. e
Answer: Option B

9. Which diode employs graded doping?
A. zener
B. LED
C. tunnel
D. step-recovery
Answer: Option D

10. Refer to this figure Identify the Schottky diode.
diodes symbol
A. a
B. b
C. c
D. d
E. e
Answer: Option E

11. LEDs are made out of
A. silicon.
B. germanium.
C. gallium.
D. silicon and germanium, but not gallium.
Answer: Option C

12. The normal operating region for a zener diode is the
A. forward-bias region.
B. reverse-bias region.
C. zero-crossing region.
D. reverse-breakdown region.
Answer: Option D

13. Refer to this figure If VIN attempts to increase, VR will
zener diodes
A. increase
B. decrease
C. remain the same
Answer: Option A

14. An LED is forward-biased The diode should be on, but no light is showing. A possible trouble might be
A. the diode is open.
B. the series resistor is too small.
C. none The diode should be off if forward-biased.
D. the power supply voltage is too high.
Answer: Option A

15. A 6.2 V zener is rated at 1 watt. The maximum safe current the zener can carry is
A. 1.61 A.
B. 161 mA.
C. 16.1 mA.
D. 1.61 mA.
Answer: Option B

16. Refer to this figure. Find the tunnel diode symbol.
diodes symbol
A. a
B. b
C. c
D. d
E. e
Answer: Option D

17. Refer to this figure If the load current increases, IR will ___ and IZ will ___.
zener diodes
A. remain the same, increase
B. decrease, remain the same
C. increase, remain the same
D. remain the same, decrease
Answer: Option D

18. The process of emitting photons from a semi-conductive material is called
A. photo-luminescence
B. gallium arsenide.
C. electo-luminescence
D. gallium phosphide
Answer: Option C

19. An 8.2 V zener has a resistance of 5 ohm. The actual voltage across its terminals when the current is 25 mA is
A. 8.2 V.
B. 125 mV.
C. 8.325 V.
D. 8.075 V.
Answer: Option C

20. What diode operates only with majority carriers?
A. laser
B. tunnel
C. Schottky
D. step-recovery
Answer: Option C

21. Refer to this figure Which symbol is correct for a photo-diode?
diodes symbol
A. a
B. b
C. c
D. d
E. e
Answer: Option C

22. What type of diode maintains a constant current?
A. LED
B. zener
C. current regulator
D. pin
E. none of the above
Answer: Option C

23. What diode is used in seven-segment displays?
A. zener
B. LED
C. laser
D. Schottky
Answer: Option B

24. Refer to this figure If VIN decreases, IR will
zener diodes
A. increase
B. decrease
C. remain the same
Answer: Option B

25. Zener diodes with breakdown voltages greater than 5 V operate predominantly in what type of breakdown?
A. avalanche
B. zener
C. varactor
D. Schottky
Answer: Option A

26. Back-to-back varactor diodes are used for what reason?
A. over-voltage protection
B. a wider tuning range
C. to eliminate harmonic distortion
D. no reason; only zeners are used in a back-to-back configuration
Answer: Option C

27. A tunnel diode is used
A. in high-power circuits.
B. in circuits requiring negative resistance.
C. in very fast-switching circuits.
D. in power supply rectifiers.
Answer: Option B

28. What type of diode is commonly used in electronic tuners in TVs?
A. varactor
B. Schottky
C. LED
D. Gunn
Answer: Option A

29. A laser diode normally emits
A. coherent light.
B. monochromatic light.
C. coherent and monochromatic light.
D. neither coherent nor monochromatic light.
Answer: Option C

30. A varactor is a pn junction diode that always operates in ___-bias and is doped to ___ the inherent capacitance of the depletion region.
A. forward, maximize
B. reverse, maximize
C. reverse, minimize
D. forward, minimize
Answer: Option B

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