Following are some of the multiple choice questions on the Power Electronics with answers that will help the students in developing their knowledge.
Power Electronics MCQ
1. Which device can be used in a chopper circuit?
2. Which of the following statements is correct in connection with the inverters?
3. The major advantage of using dual converters is that
4. In AC voltage controllers the
5. The values of duty cycle (α) lies between..........
6. The shape of the output voltage waveform in a single PWM is
7. In an inverter, if the fundamental frequency is 50 Hz, if third harmonic is eliminated, then frequencies of other components in the output voltage wave, in Hz, would be
8. The TRIAC is most sensitive in the _________ quadrants
9. All the modern AC-DC converters are using GTOs instead of SCRs because
10. In case of TRC (Time Ratio Control), _________ is varied
11. A voltage source inverter is normally employed when
12. In the ___________ type of chopper, two stage conversions takes place.
13. Dual converters provide
14. In voltage source inverters
15. In the three-phase bridge inverter, each step consists of
16. The load voltage of a chopper can be controlled by varying the..................
17. What are rheostats used for?
18. A single-phase semi-converter is having continuous conduction, as such each thyristor will conduct for an angle of
19. In the continuous conduction mode if the firing angle of the converter is increased beyond _________ degrees the converter operates in the _______ mode.
20. When a UJT is turned ON, the resistance between emitter terminal and lower base terminal ___________
21. The series-inverter control method is a/an..........
22. What is the duty cycle of a chopper ?
23. In a half wave bridge inverter circuit, the power delivered to the load by each source is given by
24. For a single phase thyristor circuit with R load & firing angle α, the conduction angle can be given by
25. In a UJT, the p-type emitter is ___________ doped
26. What is the purpose of a resistor?
27. Cycloconverter converts
28. A PWM switching scheme is used with a three phase inverter to
29. A UJT has ___________.
30. When the emitter terminal of a UJT is open, the resistance between the base terminal is generally ___________.
31. In case of circulating current type dual converters, the reactor is inserted between
32. The ____________ region in a power diode increases its reverse voltage blocking capacity.
33. The UJT may be used as ___________.
34. The Gate-Drain transfer capacitance of a MOSFET has large value in the ________________ region and small value in the ________________ region.
35. A diac has ___________ semiconductor layers
36. The device that does not have the gate terminal is ___________.
37. A single phase half wave controlled converter always operates in the ________ conduction mode.
38. The four quadrant operation of dual converters can be obtained by
39. A single phase full bridge inverter can operate in load commutation mode if load consists of
40. A single full converter alone can given a
41. A UJT is sometimes called ___________ diode.
42. 1. In case of three-phase dual converter, one of the converter circuits is fired at an angle of 60°. For both the converter circuits to have equal average output voltage, what is the value of the firing angle for the other converter circuit?
43. The process of commutating a SCR by applying a reverse voltage to an SCR through a previously charged capacitor is called as
44. How does resistance affect current?
45. The normal way to turn on a diac is by ___________.
46. Circulating current flows
47. In non-circulating current mode dual converters, the circulating current is avoided by
48. In pulse width modulation scheme, _________ is kept constant
49. A chopper may be thought as a
50. In the principle of phase control
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