1.
How many semiconductor layers does a triac have?
2.
Commutation overlap in the phase-controlled ac to dc converter is due to
3.
Thyristor as a solid state relay is useful
4.
What is the ratio of two exponential functions of time called?
6.
What is the sensing element of acceleration transducer?
7.
A modern power semiconductor device that combines the characteristics of BJT and MOSFET is
8.
The peak reverse blocking voltage of an IGBT is nearly
9.
An SCR remains turned on if the anode current is more than
10.
Power electronics deals with the control of ac power at what frequencies essentially?
11.
Which equation defines the intrinsic stand off ratio (y) of UJTs?
12.
When the temperature increases, the inter-base resistance of a UJT
13.
An emitter follower regulator has the following disadvantage :
14.
After firing an SCR, the gate pulse is removed . The current in the SCR will
15.
How many pn junction does SCRs have?
16.
Which semiconductor power device, out of the following, is not a current triggered device?
17.
When the emitter terminal of a UJT is open, the resistance between the base-terminals is generally
18.
The output voltage in a switching regulator for an input Vin and duty cycle δ is
19.
It is preferable to use a train of pulse of high frequency for gate triggering of SCR in order to reduce
20.
A resistor connected across the gate and cathode of an SCR
21.
The basic difference between a series regulator and a shunt regulator is
23.
Which one of the following controls reduces the size of the transformer in a switch mode ac power supply ?
24.
The latching current is _________ than the holding current
25.
The gate of an SCR is _______with respect to its cathode.
27.
The p-type emitter of a UJT is ______doped.
28.
The typical turn-off time of an SCR is about
29.
The input power factor of the converter is
30.
The dv/dt effect in SCR can result in
31.
The voltage across an SCR when it is turned on is about
32.
Carrier frequency gate drive is used for turn-on of a thyristor to reduce.
33.
Most SCRs can be turned-off by voltage reversal during negative half cycle of the ac supply for
35.
In order to get best results per unit cost, the heat sinks, on which the thyristors are mounted , are made of
36.
In a feedback series regulator circuit, the output voltage is regulated by controlling the
38.
The sharing of the voltage between thyristors operating in series is influenced by their
39.
To turn off the SCR, which of the following is done?
40.
A diac has how many semiconductor layers?
41.
Which is four terminal device
42.
The V-I characteristics for a triac in the first and third quadrants are essentially identical to those of in the quotation.
43.
A diac has how many terminals?
44.
Which of the following devices does not belong to the transistor family?
45.
Two thyristor of same rating and same specifications
46.
What are some areas where GTO is applicable?
47.
Thyristor is nothing but a
48.
Latching current of an SCR is
49.
Which of the following configurations is used for both motoring and regenerative braking?
50.
A triac can pass a portion of half cycle through the load
