GATE EE
Power Electronics
Power Semiconductor Devices
Previous Years Questions

## Marks 1

A charger supplies 100 W at 20 V for charging the battery of a laptop. The power devices, used in the converter inside the charger, operate at a switc...
Four power semiconductor devices are shown in the figure along with their relevant terminals. The device(s) that can carry dc current continuously in ...
For the power semiconductor devices $$IGBT, MOSFET,$$ Diode and Thyristor, which one of the following statements is TRUE?
A steady dc current of 100 A is flowing through a power module (S, D) as shown in Figure (a). The V-I characteristics of the IGBT (S) and the diode (D...
Figure shows four electronic switches $$(i), (ii), (iii)$$ and $$(iv).$$ Which of the switches can block voltages of either polarity (applied between ...
The typical ratio of latching current to holding current in a $$20$$ $$A$$ thyristor is
Circuit turn-off time of an $$SCR$$ is defined as the time
Figure shows a composite switch consisting of a power transistor $$(BJT)$$ in series with a diode. Assuming that the transistor switch and the diode a...
An $$SCR$$ is considered to be a semi - controlled device because
The conduction loss versus device current characteristic of a power $$MOSFET$$ is best approximated by
A bipolar junction transistor $$(BJT)$$ is used as a power control switch by biasing it in the cut-off region (OFF state) or in the saturation region ...
The triggering circuit of a thyristor is shown in figure. The thyristor requires a gate current of $$10$$ $$mA,$$ for guaranteed turn-on. The value of...
Figure shows a thyristor with the standard terminations of anode $$(A),$$ cathode $$(K),$$ gate $$(G)$$ and the different junctions named $$J1, J2,$$ ...
Figure shows a $$MOSFET$$ with an integral body diode. It is employed as a power switching device in the ON and OFF states through appropriate control...
The $$MOSFET$$ switch in its on - state may be considered equivalent to
The uncontrolled electronic switch employed in power electronic converters is
In a commutation circuit employed to turn off an $$SCR$$, Satisfactory turn-off is obtained when.
If a diode is connected in anti - parallel with a thyristor, then
Which semiconductor power device out of the following is not a current triggered device?
The Triac can be used only in
Which of the following does not cause permanent damage of an $$SCR?$$
Figure, show two thyristors each rated $$500A$$ (continuous) sharing a load current. Current through thyristor $$y$$ is $$120A.$$ The current through ...
A triac can be triggered by a gate pulse of __________ polarity
A switched mode power supply operating at $$20$$ $$kHz$$ to $$100$$ $$kHz$$ range uses as the main switching element
The thermal resistance between the body of a power semiconductor device and the ambient is expressed as

## Marks 2

The $$SCR$$ in the circuit shown has a latching current of $$40$$ $$mA.$$ A gate pulse of $$50$$ $$\mu s$$ is applied to the $$SCR$$. The maximum valu...
Thyristor $$T$$ in the figure below is initially off and is triggered with a single pulse of width $$10\mu s.$$ It is given that $$L = \left( {{{100} ... Match the switch arrangements on the top row to be steady$$-$$state$$V$$-$$I$$characteristics on the lower row. The steady state operating point... A$$1:1$$pulse transformer$$(PT)$$is used to trigger the$$SCR$$in the adjacent figure. The$$SCR$$is rated at$$1.5kV$$,$$250A$$with... A$$1:1$$pulse transformer$$(PT)$$is used to trigger the$$SCR$$in the adjacent figure. The$$SCR$$is rated at$$1.5kV$$,$$250A$$with... An$$SCR$$having a turn ON time of$$5\,\,\mu \,\,\sec $$, latching current of$$50mA$$and holding current of$$40mA$$is triggered by a s... The figure shows the voltage across a power semiconductor device and the current through the device during a switching transition. Is the transition a... An electronic switch$$S$$is required to block voltages of either polarity during its OFF state as shown in figure (a). This switch is required to c... A$$MOSFET$$rated for$$15 A,$$carries a periodic current as shown in figure. The ON state resistance of the MOSFET is$$0.15\Omega . The ave...
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