Power Electronics (3140915) MCQs

MCQs of DC-AC converters – Inverters

Showing 51 to 60 out of 100 Questions
3 4 5 6 7 8
51.
What is the peak value of phase voltage in case of 3-phase VSI with 180° mode. The supply side consists of a constant dc voltage source of Vs.
(a) Vs
(b) 3Vs/2
(c) 2Vs/3
(d) 3Vs
Answer:

Option (c)

52.
The 120° mode of operation of a three phase bridge inverter requires ___________ number of steps.
(a) 2
(b) 4
(c) 6
(d) 8
Answer:

Option (c)

53.
In case of the 120° mode of operation, __________ devices conduct at a time.
(a) 2
(b) 3
(c) 4
(d) none of the mentioned
Answer:

Option (a)

54.
Safe commutation can be achieved in case of the ____________ operating mode.
(a) 180°
(b) 120°
(c) 360°
(d) none of the mentioned
Answer:

Option (b)

55.
The peak value of the line voltage in case of 120° mode of operation of a three-phase bridge inverter is
(a) Vs/2
(b) 3Vs/2
(c) Vs/√2
(d) Vs
Answer:

Option (d)

56.
The external control of ac output voltage can be achieved in an inverter by
(a) connecting a cyclo-converter
(b) connecting an ac voltage controller between the output of the inverter and the load
(c) connecting an ac voltage controller between the dc source and inverter
(d) connecting an ac voltage controller between the load and the dc source
Answer:

Option (b)

57.
The series-inverter control method is a/an
(a) internal voltage control method
(b) external frequency control method
(c) external voltage control method
(d) none of the mentioned
Answer:

Option (c)

58.
External control of dc input voltage can be obtained by the use of a
(a) transformer
(b) chopper
(c) inverter
(d) converter
Answer:

Option (b)

59.
In the external control of dc input voltage
(a) a chopper is placed just after the inverter block
(b) a chopper is placed just after the filter block
(c) a chopper is placed before the filter and the inverter block
(d) none of the mentioned
Answer:

Option (c)

60.
__________ method is an internal method for controlling the inverter output voltage.
(a) series connection of inverters
(b) chopper method
(c) commutating capacitor
(d) pulse width modulation
Answer:

Option (d)

Showing 51 to 60 out of 100 Questions
3 4 5 6 7 8