1.
When the firing angle of SCR is increased, its output
2.
When SCR starts conducting, then ______losses all control.
3.
The value of anode current required to maintain the conduction of an SCR even though the gate signal is removed is called as the
4.
Turned-on of a thyristor takes place when
5.
When the SCR is OFF, the current in the circuit is
6.
When UJTs is turned on, the resistance between emitter terminal and lower base terminal
7.
What is dimensionless parameter of the second-order characteristic equation?
8.
In a thyristor dc chopper, which type of commutation results in best performance ?
9.
Turn-on and turn-off times of transistor depend on
10.
Switching regulators are also called
11.
A thyristor controlled reactor, the firing angle of thyristor is to be controlled in the range of
12.
Once an SCR is turned on, it remains so until the anode current goes below
13.
A transduction principle used primarily in optical sensors.
14.
Which one of the following statements is correct? In the case of load regulation
15.
Which of the following can change the angle of conduction in SCR?
16.
Triacs can not be used in ac voltage regulator for a
17.
The device commonly used for triggering a triac is
18.
An emitter follower regulator has the following disadvantage :
19.
The most suitable device for high frequency inversions in SMPS is
20.
A normally operated SCR has an anode which is _____ with respect to cathode.
21.
Which of the following is a four-layer diode with an anode gate and a cathode gate?
22.
The snubber circuit is used in thyristor circuits for
23.
The terminals of a power MOSFET are called
24.
The three terminals of an SCR are the
25.
In a feedback series regulator circuit, the output voltage is regulated by controlling the
26.
Which one of the following is NOT the advantage of solid state switching of ac capacitors into ac supply over relay-based switching?
27.
The V-I characteristics for a triac in the first and third quadrants are essentially identical to those of in the quotation.
28.
A single-phase full converter gives maximum and minimum output voltage at firing angles of
29.
A triac is equivalent to two SCRs
30.
A freewheeling diode in a phase-controlled rectifier
31.
An SCR is made of silicon and not germanium because silicon.
32.
The main advantage of IGBT over SCR in power electronics is
33.
Thyristor is nothing but a
34.
Which transistor conducts current in both directions when turned on?
35.
Which of the following configurations is used for both motoring and regenerative braking?
36.
An SCR chopper circuit supplies power to a dc motor , what will be the nature of motor armature current?
37.
Which of the following devices should be used as a switch in a low power switched mode power supply (SMPS) ?
38.
Why is an external pass resistor used in a voltage regulator ?
39.
The minimum gate current which can turn on SCR is called:
40.
A boost-regulator has an input voltage of 5V and the average output voltage of 15 V. The duty cycle is
41.
The sharing of the voltage between thyristors operating in series is influenced by their
42.
What region lies between the peak point and valley point of UJT emitter characteristic?
43.
What is a solid state equivalent of a gas filled triode?
44.
What is a three terminal device used to control large current to a load?
45.
Freewheeling diode at the output of a rectifier allows
47.
An SCR is a _____ triggered device.
48.
The triac can be used only in
49.
The p-type emitter of a UJT is ______doped.
50.
Natural commutation can be used in:
