Power Electronics (3140915) MCQs

MCQs of DC-AC converters – Inverters

Showing 81 to 90 out of 100 Questions
6 7 8 9 10
81.
Output voltage of a single-phase bridge inverter, fed from a fixed dc source is varied by
(a) varying the switching frequency
(b) pulse-width modulation
(c) pulse amplitude modulation
(d) all of the mentioned
Answer:

Option (b)

82.
Which of the following is used as a harmonic reduction technique in inverters?
(a) Amplitude modulation
(b) Cycloconverter control
(c) Transformer connection
(d) Series connection of two inverters
Answer:

Option (c)

83.
For harmonic reduction by transformer connection, the output voltages from the two inverters must be
(a) similar and in-phase with each other
(b) dissimilar but in-phase with each other
(c) similar but phase shifted from each other
(d) dissimilar and phase shifted from each other
Answer:

Option (c)

84.
The output voltage obtained by connecting two inverters through a transformer is a
(a) square wave
(b) sine wave
(c) quasi-square wave
(d) none of the mentioned
Answer:

Option (c)

85.
Pulses of different widths and heights are superimposed in case of __________ harmonic reduction technique.
(a) transformer connection
(b) pulse width modulation
(c) stepped-wave inverter
(d) none of the mentioned
Answer:

Option (c)

86.
In case of stepped wave inverters,
(a) both the transformers have 1:1 turns ratio
(b) both the transformers have 1:2 turns ratio
(c) both the transformers have different transformer ratio
(d) none of the mentioned
Answer:

Option (c)

87.
In stepped wave inverters, one of the inverters are gated such as to obtain
(a) one level modulation
(b) two level modulation
(c) zero level modulation
(d) none of the mentioned
Answer:

Option (b)

88.
In three-level modulation
(a) the output voltage is zero in the first half cycle.
(b) the output voltage either zero or positive in the first half cycle.
(c) the output voltage either zero or negative in the first half cycle.
(d) the output voltage either zero, positive or negative in the first half cycle.
Answer:

Option (d)

89.
The waveform obtained by __________ is more near to a sinusoidal wave
(a) PWM inverters
(b) Stepped wave inverters
(c) parallel connected inverters
(d) None of the mentioned
Answer:

Option (b)

90.
If, for a single-phase half-bridge inverter, the amplitude of output voltage is Vs and the output power is P, then their corresponding values for a single-phase full-bridge inverter are
(a) Vs, P
(b) Vs/2 , P/2
(c) 2.Vs, 2P
(d) 2.Vs, P
Answer:

Option (c)

Showing 81 to 90 out of 100 Questions
6 7 8 9 10