## 1. A Varactor Diode performs as

- A variable resistor
- A variable capacitor
- A switching device
- none of these

**Answer – (2)**

## 2. When PN junction diode is forward bias, forward current is dominated by

- The diffusion current
- The displacement current
- The drift current
- The drift or diffusion current

**Answer** – (1)

**3. **Storage capacitance in the PN junction is due to

- The majority carriers
- The minority carriers
- The majority and the minority carriers, equally
- None of these

**Answer** – (3)

## 4. A varicap is worked in

- The reverse biasing condition
- The forward biasing condition
- Without biasing condition
- None of these

**Answer** – (1)

## 5. Which has -ve resistance region of operation?

- The Zener type
- The Tunnel type
- The photodiode
- The LED

**Answer** – (2)

## 6. IMPATT diode is

- A negative conductance microwave device
- A high frequency rectifying device
- A degenerate semiconductor device
- A bulk negative differential conductance device

**Answer** – (1)

## 7. Operation of Gunn diode is explained with

- The transferred electrons effect
- The avalanche transmit time effect
- The tunneling effect
- The Schottky effect

**Answer** – (3)

## 8. Tunnel Diode is employed in

- The Micro-wave Oscillator design
- The RF Oscillator design
- An audio oscillator design
- A Video amplifier design

**Answer** – ( 3 )

## 9. Reverse saturation current of the PN junction diode is working as

- The diffusion current
- The drift current
- The displacement current
- None of these

**Answer** – (2)

## 10. I is PN junction diode forward current. Diffusion capacitance is proportional to

- I
^{1/2} - I
^{3/2} - I
- I
^{2}

**Answer** – (1)

## 11. Zener effect is operated at

- high reverse voltage and for heavily doped junction
- low reverse voltage and for heavily doped junction
- high reverse voltage and for lightly doped junction
- low reverse voltage and for lightly doped junction

**Answer** – (2)

## 12. IMPATT diode works by the mechanism of

- electron tunneling
- transferred electrons
- avalanche multiplication
- none of these

**Answer** – (1)

## 13. The Schottky diode is used in high speed operation because of

- small current potential
- high speed of electrons
- small size
- insignificant storage delay

**Answer** – (2)

## 14. Gun diode is utilized in

- The microwave oscillator
- The RF oscillator
- An audio oscillator
- An audio amplifier

**Answer** – (1)

## 15. Zener diodes are

- specially doped PN junction
- normally doped PN junction
- lightly doped PN junction
- none of these

**Answer** – (1)

## 16. Diffusion current in a PN junction is influenced by

- concentration gradient of carriers
- applied voltage
- concentration of carriers
- none of these

**Answer** – (1)

## 17. If a voltage (+ve.) is connected to an n-type semiconductor through the metal plate, the barrier in between

- Will increases
- Will decreases
- Will remains same
- none of these, will happen

**Answer** – (1)

## 18. We can connect photodetector diode in

- both in forward bias and reverse bias
- forward bias
- reverse bias
- no need to connect any bias

**Answer** – (3 )

## 19. In photodiode, electron- hole pairs are engendered, if

- The energy of incident photon (hf) < Eg
- The energy of incident photon (hf)> Eg
- The energy of incident photon (hf) = Eg
- The energy of incident photon (hf) >> Eg

**Answer** – (2)

## 20. Solar cell works in

- I-Quadrant
- IV-Quadrant
- II-Quadrant
- III-Quadrant

**Answer** – (2)

## 21. Avalanche breakdown primarily be influenced by the phenomenon of

- The impact ionization
- The field ionization
- The particle collision
- The impurity doping

**Answer** – (1)

## 22. The Solar Cell’s V-I plot Quadrant will be at

- I
- II
- III
- IV

**Answer** – (4)

## 23. Which of the following type does not possess a negative resistance region in its characteristics?

- The Tunnel type
- The Gun type
- The Zener type
- The IMPATT type

**Answer** – (3)

## 24. What will be the reading of voltmeter, if it is connected using an unbiased Germanium PN junction diode?

- 0 Volt
- 0.3 Volt
- 0.6 Volt
- 1.0 Volt

**Answer** – (1)

## 25. Photodetector is following

- triangular device
- square law device
- linear device
- both a & b

**Answer** – ( 3 )

## 26. LED works on the principle of

- photoluminescence
- electroluminescence
- cathodoluminescence
- radioluminescence

**Answer** – (1)

## 27. PIN diode has

- p and n layers separated by 1 layer
- p+ and n+ layers separated by 1 layer
- p- and n- layers separated by 1 layer
- either b or c

**Answer** – (2)

**28. **** A voltage variable capacitance can be realized in**

- The Avalanche type
- The Zener type
- The Schottky type
- The Varicap or varactor type

**Answer** – (4)

## 29. In a voltage regulator circuit, the maximum value

- 2.5 mA load current
- 0.9 mA load current
- 1.6 mA load current
- 3.4 mA load current

**Answer** – (4)

## 30. The Varicap are ordinarily used

- As a voltage controlled capacitance circuitry
- as a constant current source
- as a voltage multiplier circuitry
- as a constant voltage source

**Answer** – (1)

**To know more about diodes click here**

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