Power Electronics (3140915) MCQs

MCQs of DC-AC converters – Inverters

Showing 61 to 70 out of 100 Questions
61.
In the PWM method
(a) external commutating capacitors are required
(b) more average output voltage can be obtained
(c) lower order harmonics are minimized
(d) higher order harmonics are minimized
Answer:

Option (c)

62.
Which of the following is not a PWM technique?
(a) Single-pulse width modulation
(b) Multiple-pulse width modulation
(c) riangular-pulse width modulation
(d) Sinusoidal-pulse width modulation
Answer:

Option (c)

63.
In pulse width modulation
(a) the output voltage is modulated
(b) the input voltage is modulated
(c) the gating pulses are modulated
(d) none of the mentioned
Answer:

Option (c)

64.
In the single-pulse width modulation method, the output voltage waveform is symmetrical about __________
(a) π
(b)
(c) π/2
(d) π/4
Answer:

Option (c)

65.
The shape of the output voltage waveform in a single PWM is
(a) square wave
(b) triangular wave
(c) quasi-square wave
(d) sine wave
Answer:

Option (c)

66.
In the single-pulse width modulation method, when the pulse width of 2p is equal to its maximum value of π radians, then the fundamental component of output voltage is given by
(a) Vs
(b) 4Vs/π
(c) 0
(d) 2Vs/π
Answer:

Option (b)

67.
Several equidistant pulses per half cycle are used in ___________ type of modulation technique.
(a) single-pulse
(b) multiple-pulse
(c) sine-pulse
(d) equidistant-pulse
Answer:

Option (b)

68.
In the Multi-Pulse Moduation method, the comparator is given _______ and _______ types of waveform at its input
(a) square, sine
(b) square, quasi-square
(c) sine, triangular
(d) square, triangular
Answer:

Option (d)

69.
In the multiple pulse width modulation method, the firing pulses are generate during the interval when the
(a) triangular wave exceeds the square modulating wave
(b) square modulating wave exceeds the triangular wave
(c) square wave amplitude is same as the triangular wave’s amplitude
(d) none of the mentioned
Answer:

Option (a)

70.
In ___________ type of modulation method, the pulse width is not equal for all the pulses.
(a) multiple pulse width modulation
(b) single pulse width modulation
(c) sinusoidal pulse width modulation
(d) none of the mentioned
Answer:

Option (c)

Showing 61 to 70 out of 100 Questions