1.
The ON voltage and forward breakover of an SCR depend on the
2.
The value of anode current required to maintain the conduction of an SCR even though the gate signal is removed is called as the
3.
A thyristor can be termed as
4.
What is the typical turn-on time of an SCR?
5.
Freewheeling diode at the output of a rectifier allows
6.
Thyristor is a semiconductor switch which is
7.
In a switching regulator , the control transistor is conducting
8.
When UJTs is turned on, the resistance between emitter terminal and lower base terminal
9.
A UJT is sometimes called a______diode.
10.
An SCR chopper circuit supplies power to a dc motor , what will be the nature of motor armature current?
11.
When the temperature increases, the intrinsic stand off ratio
12.
To turn on the UJT, the forward bias on emitter diode should be______ the peak point voltage.
13.
A diac has how many terminals?
14.
The voltage across an SCR when it is turned on is about
15.
For a BJT α = 0.98, then β =
16.
Which of the following does not cause permanent damage to an SCR?
17.
An SCR is a solid state equivalent of which tube?
18.
The three terminals of a triac are
19.
Which one of the following statements is correct? In the case of load regulation
20.
Power electronics deals with the control of ac power at what frequencies essentially?
21.
Line regulation is determined by
23.
Which of the following is a four-layer diode with an anode gate and a cathode gate?
25.
Which one of the following is used as the main switching element in a switched mode power supply operating in 20 kHz to 100 kHz range?
26.
Turn-off time of a thyristor
27.
When an SCR is combined to a switch, it is considered as a switch.
28.
In an LC series circuit connected to a dc supply of E volts via a thyristor when it turns off, the voltage that appears across the thyristor is
29.
di/dt protection is provided to the thyristor by
30.
Which transistor conducts current in both directions when turned on?
31.
The triac can be used only in
32.
The SCR can exercise control over of ac supply.
33.
What is the required gate triggering current of GTO?
34.
What are some areas where GTO is applicable?
36.
The basic difference between a series regulator and a shunt regulator is
37.
Why is an external pass resistor used in a voltage regulator ?
38.
A boost-regulator has an input voltage of 5V and the average output voltage of 15 V. The duty cycle is
40.
Two thyristor of same rating and same specifications
41.
An emitter follower regulator has the following disadvantage :
42.
When the supply voltage exceeds the breakover voltage of an SCR, it
43.
ECG stands for electrocardiography while EEG stands for?
44.
In a chopper fed dc drive , the chopping frequency is approximately equal to
45.
Which one of the following controls reduces the size of the transformer in a switch mode ac power supply ?
46.
Which one of the following statements regarding the two-transistor model of the p-n-p-n four-layer device is correct?
47.
Which is the control element in an SCR?
48.
The peak reverse blocking voltage of an IGBT is nearly
49.
What is the control element in an SCR?
50.
In ac motor control, the ratio of voltage-to-frequency is maintained at constant value
