Semiconductor Devices – MCQs

1. : What is the most commonly used semiconductor material?
(A) Germanium
(B) Gallium Arsenide
(C) Silicon
(D) Indium Phosphide

2. : What type of semiconductor is formed when a trivalent impurity is added to silicon?
(A) Intrinsic
(B) N-type
(C) P-type
(D) Degenerate

3. : Which of the following is a unipolar device?
(A) BJT
(B) JFET
(C) SCR
(D) MOSFET

4. : What is the function of a diode?
(A) Amplification
(B) Rectification
(C) Oscillation
(D) Switching only

5. : What is the voltage drop across a silicon diode when forward-biased?
(A) 0.1V
(B) 0.3V
(C) 0.7V
(D) 1.1V

6. : Which terminal of a transistor controls the operation?
(A) Emitter
(B) Base
(C) Collector
(D) Gate

7. : What is the primary function of a Zener diode?
(A) Oscillation
(B) Amplification
(C) Voltage regulation
(D) Switching

8. : Which device can amplify weak signals?
(A) Diode
(B) Transistor
(C) Resistor
(D) Capacitor

9. : A depletion-type MOSFET can operate in which mode(s)?
(A) Depletion mode only
(B) Enhancement mode only
(C) Both depletion and enhancement
(D) Neither

10. : In a BJT, what is the function of the emitter?
(A) Collect electrons
(B) Control current
(C) Emit charge carriers
(D) Block current

11. : Which of the following is a characteristic of a Schottky diode?
(A) High forward voltage drop
(B) Slow switching speed
(C) Low forward voltage drop
(D) Used for amplification

12. : What is the majority carrier in an N-type semiconductor?
(A) Holes
(B) Electrons
(C) Protons
(D) Ions

13. : What kind of junction is formed in a PN diode?
(A) Ohmic junction
(B) Metal-semiconductor junction
(C) PN junction
(D) Thermal junction

14. : Which of the following is used in power applications?
(A) Tunnel diode
(B) Varactor diode
(C) Power MOSFET
(D) Photodiode

15. : Which region of a transistor is lightly doped?
(A) Emitter
(B) Base
(C) Collector
(D) Substrate

16. : A diode conducts in which direction?
(A) Forward bias only
(B) Reverse bias only
(C) Both directions
(D) No direction

17. : The reverse breakdown in Zener diode occurs due to:
(A) Avalanche effect
(B) Tunneling effect
(C) Both A and B
(D) Magnetic field

18. : Which semiconductor device acts like a variable resistor?
(A) BJT
(B) FET
(C) Diode
(D) Varactor

19. : What type of transistor is widely used in digital ICs?
(A) BJT
(B) JFET
(C) MOSFET
(D) UJT

20. : Which of the following is not a terminal of BJT?
(A) Emitter
(B) Collector
(C) Base
(D) Gate

21. : The current gain of a BJT in common-emitter configuration is denoted by:
(A) α
(B) β
(C) γ
(D) δ

22. : Which device is used to convert light into electrical energy?
(A) LED
(B) Solar Cell
(C) Photodiode
(D) Zener Diode

23. : Which device emits light when forward-biased?
(A) Varactor diode
(B) Schottky diode
(C) LED
(D) Zener diode

24. : Which of the following is a unidirectional device?
(A) BJT
(B) Diode
(C) Triac
(D) SCR

25. : A JFET is normally in which state when no gate voltage is applied?
(A) OFF
(B) ON
(C) Saturated
(D) Biased