1. Power electronics deals with
A) Control of AC signals
B) Control of power using electronic devices
C) Control of DC signals
D) Amplification of signals
Answer: B) Control of power using electronic devices
2. The full form of SCR is
A) Silicon Control Rectifier
B) Semiconductor Controlled Rectifier
C) Silicon Controlled Rectifier
D) Semiconductor Control Regulator
Answer: C) Silicon Controlled Rectifier
3. SCR is a
A) Unidirectional device
B) Bidirectional device
C) Current controlled device
D) Voltage controlled device
Answer: A) Unidirectional device
4. The number of PN junctions in an SCR is
A) 1
B) 2
C) 3
D) 4
Answer: C) 3
5. The three terminals of an SCR are
A) Anode, Cathode, Base
B) Source, Drain, Gate
C) Anode, Cathode, Gate
D) Collector, Emitter, Base
Answer: C) Anode, Cathode, Gate
6. A TRIAC can conduct in
A) One direction
B) Both directions
C) Only forward direction
D) Only reverse direction
Answer: B) Both directions
7. The symbol of DIAC resembles
A) SCR
B) TRIAC
C) Two diodes connected in series
D) Two diodes connected in parallel opposite
Answer: D) Two diodes connected in parallel opposite
8. The full form of IGBT is
A) Insulated Gate Bipolar Transistor
B) Internal Gate Bipolar Transistor
C) Insulated Grid Bipolar Transistor
D) Integrated Gate Bipolar Transistor
Answer: A) Insulated Gate Bipolar Transistor
9. Inverter converts
A) DC to AC
B) AC to DC
C) AC to AC
D) DC to DC
Answer: A) DC to AC
10. Converter converts
A) AC to AC
B) AC to DC
C) DC to DC
D) DC to AC
Answer: B) AC to DC
11. Chopper converts
A) DC to AC
B) AC to DC
C) DC to DC
D) AC to AC
Answer: C) DC to DC
12. The device used for switching in power electronics is
A) Diode
B) Transistor
C) SCR
D) All of these
Answer: D) All of these
13. The gate of an SCR is used to
A) Turn ON the SCR
B) Turn OFF the SCR
C) Increase current
D) Decrease voltage
Answer: A) Turn ON the SCR
14. Holding current is
A) Minimum current to turn on SCR
B) Minimum current to keep SCR ON
C) Maximum current of SCR
D) Leakage current of SCR
Answer: B) Minimum current to keep SCR ON
15. The SCR conducts when
A) Forward biased
B) Reverse biased
C) Forward biased and gate is triggered
D) None of these
Answer: C) Forward biased and gate is triggered
16. The turn OFF process of SCR is called
A) Conduction
B) Commutation
C) Triggering
D) Latching
Answer: B) Commutation
17. In half-wave rectifier, the SCR conducts for
A) Full cycle
B) Half cycle
C) Both cycles
D) No conduction
Answer: B) Half cycle
18. MOSFET is a
A) Current controlled device
B) Voltage controlled device
C) Power controlled device
D) None of these
Answer: B) Voltage controlled device
19. The triggering circuit is used to
A) Increase voltage
B) Reduce current
C) Control firing angle of SCR
D) Convert DC to AC
Answer: C) Control firing angle of SCR
20. Power electronics uses
A) Linear devices
B) Nonlinear devices
C) Amplifiers
D) Sensors
Answer: B) Nonlinear devices
21. Freewheeling diode is used to
A) Reduce harmonics
B) Protect load from negative voltage
C) Provide current path for inductive load
D) Increase conduction angle
Answer: C) Provide current path for inductive load
22. A diode conducts current when it is
A) Forward biased
B) Reverse biased
C) Open circuit
D) No voltage applied
Answer: A) Forward biased
23. The unit of firing angle is
A) Volt
B) Ampere
C) Radian or degree
D) Hertz
Answer: C) Radian or degree
24. In a full-wave rectifier, output frequency is
A) Equal to input frequency
B) Twice the input frequency
C) Half of input frequency
D) Zero
Answer: B) Twice the input frequency
25. The output of an uncontrolled rectifier is
A) Pure DC
B) Pulsating DC
C) AC
D) Constant voltage
Answer: B) Pulsating DC
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