1. : What is the main function of a power electronic converter?
(A) Signal amplification
(B) Power conversion
(C) Frequency modulation
(D) Data transmission
2. : Which device is commonly used in power electronics for switching applications?
(A) BJT
(B) MOSFET
(C) SCR
(D) All of the above
3. : The full form of SCR is:
(A) Silicon Controlled Rectifier
(B) Semiconductor Controlled Regulator
(C) Simple Current Relay
(D) Solid Capacitor Resistor
4. : Which one of these is a unidirectional device?
(A) Diode
(B) TRIAC
(C) MOSFET
(D) IGBT
5. : A TRIAC can conduct current in:
(A) Only forward direction
(B) Only reverse direction
(C) Both directions
(D) Alternating cycles only
6. : What is the typical application of a chopper in power electronics?
(A) AC to DC conversion
(B) DC to DC voltage regulation
(C) Frequency control
(D) Data communication
7. : Inverters convert:
(A) AC to DC
(B) DC to AC
(C) AC to AC
(D) DC to DC
8. : The operation of a power MOSFET is based on:
(A) Junction principle
(B) Field-effect principle
(C) Bipolar operation
(D) Thermionic emission
9. : Which device combines the advantages of BJT and MOSFET?
(A) SCR
(B) TRIAC
(C) IGBT
(D) UJT
10. : What is the main drawback of SCR in switching circuits?
(A) Cannot handle high voltages
(B) Cannot be turned off by gate signal
(C) Low current rating
(D) Expensive
11. : The firing angle of an SCR is defined as:
(A) Time when the SCR turns off
(B) Time when the anode current drops
(C) Time from zero voltage to the gate trigger
(D) Time from zero crossing to when gate signal is applied
12. : Which converter converts AC of one frequency to AC of another frequency?
(A) Chopper
(B) Inverter
(C) Cycloconverter
(D) Rectifier
13. : In a full-wave rectifier, the number of diodes used is:
(A) 1
(B) 2
(C) 3
(D) 4
14. : The advantage of using IGBT over MOSFET is:
(A) Lower cost
(B) Faster switching
(C) Higher voltage handling
(D) Lower gate drive
15. : A snubber circuit is used in power electronics to:
(A) Reduce noise
(B) Control temperature
(C) Protect device from voltage spikes
(D) Increase power output
16. : Which of the following is an uncontrolled device?
(A) SCR
(B) Diode
(C) TRIAC
(D) IGBT
17. : Which material is commonly used for high-power semiconductor devices?
(A) Germanium
(B) Gallium Arsenide
(C) Silicon
(D) Copper
18. : The term “commutation” in SCRs refers to:
(A) Turning ON
(B) Turning OFF
(C) Increasing frequency
(D) Boosting current
19. : A buck converter is used to:
(A) Increase DC voltage
(B) Decrease DC voltage
(C) Convert AC to DC
(D) Convert DC to AC
20. : The main drawback of a linear voltage regulator is:
(A) High efficiency
(B) Simple design
(C) Heat dissipation
(D) Low cost
21. : The basic component of a PWM-based inverter is:
(A) Transformer
(B) Inductor
(C) Switch (like MOSFET/IGBT)
(D) Capacitor
22. : A boost converter increases:
(A) Current
(B) Frequency
(C) Voltage
(D) Power loss
23. : In a three-phase inverter, the number of switching devices required is:
(A) 2
(B) 4
(C) 6
(D) 8
24. : Which power electronic device is suitable for fast switching applications?
(A) SCR
(B) TRIAC
(C) IGBT
(D) MOSFET
25. : The efficiency of power electronic devices is generally:
(A) Below 50%
(B) Between 60–70%
(C) Above 85%
(D) Exactly 100%