MCQs of DC-AC converters – Inverters (Power Electronics - 3140915)

Power Electronics (3140915) MCQs

MCQs of DC-AC converters – Inverters

Showing 91 to 90 out of 100 Questions

91.

In voltage source inverters

(a)	load voltage waveform v₀ depends on load impedance Z, whereas load current waveform i₀ does not depend on Z
(b)	Both v₀ and i₀ depend on Z
(c)	v₀ does not depend on Z whereas i₀ depends on Z
(d)	both v₀ and i₀ do not depend upon Z.

92.

In single-pulse modulation of PWM inverters, third harmonic can be eliminated if pulse width is equal to

(a)	30°
(b)	60°
(c)	120°
(d)	150°

93.

In single-pulse modulation of PWM inverters, fifth harmonic can be eliminated if pulse width is equal to

(a)	30°
(b)	72°
(c)	36°
(d)	108°

94.

In single-pulse modulation of PWM inverters, the pulse width is 120°. For an input voltage of 220 V, the r.m.s. value of output voltage is

(a)	179.63 V
(b)	254.04 V
(c)	127.02 V
(d)	185.04 V

95.

In single-pulse modulation used in PWM inverters, Vs is the input de voltage. For eliminating third harmonic, the magnitude of rms value of fundamental component of output voltage and pulse width are respectively

(a)	$\frac{2 \sqrt{2}}{π} V_{s}, 120 °$
(b)	$\frac{4}{π} V_{s}, 60 °$
(c)	$\frac{2 \sqrt{2}}{π} V_{s}, 60 °$
(d)	$\frac{4}{π} V_{s}, 120 °$

96.

In multiple-pulse modulation used in PWM inverters, the amplitude~ of reference square wave and triangular carrier wave are respectively 1 V and 2 V. For generating 5 pulses per half cycle, the pulse width should be

(a)	36°
(b)	24°
(c)	18°
(d)	12°

97.

In multiple-pulse modulation used in PWM inverters, the amplitude and frequency for triangular carrier and square reference signals are ·respectively 4 V, 6 kHz and 1 V, 1 kHz. The number of pulses per half cycle and pulse width are respectively

(a)	6, 90°
(b)	3, 45°
(c)	4, 60°
(d)	3, 40°.

98.

In sinusoidal-pulse modulation used in PWM inverters, amplitude and frequency for triangular carrier and sinusoidal reference signals are respectively 5 V, 1 kHz and 1 V, 50 Hz. If zeros of the triangular carrier and reference sinusoid coincide, then the. modulation index and order of significant harmonics are respectively

(a)	0.2, 9 and 11
(b)	0.4, 9 and 11
(c)	0.2, 17 and 19
(d)	0.2, 19 and 21

99.

Which of the following statement is correct in connection with inverters:

(a)	VSI and CSI both require feedback diodes
(b)	Only CSI requires feedback diodes
(c)	GTOs can be used in CSI
(d)	Only VSI requires feedback diodes

100.

A single-phase full bridge VSI has inductor L as the load. For a constant source voltage, the current through the inductor is

(a)	square wave
(b)	trianguliu wave
(c)	sine wave
(d)	pulsed wave

Showing 91 to 90 out of 100 Questions