1.
When SCR starts conducting, then ______losses all control.
2.
Which is four terminal device
4.
Turn-off time of a thyristor
5.
Why is an external pass resistor used in a voltage regulator ?
6.
An SCR is made of what material?
7.
When the temperature increases, the inter-base resistance of a UJT
8.
Which of the following can change the angle of conduction in SCR?
9.
Dc to dc converter or chopper can
10.
To turn on the UJT, the forward bias on emitter diode should be______ the peak point voltage.
11.
Which one of the following is the main advantage of SMPS over linear power supply ?
12.
Consider the following semiconductor devices:
1. Triac 2. Thyristor 3. amplifying gate thyristor
The correct sequence of these devices in increasing order of their di/dt capabilities is
13.
AC power in a load can be controlled by connecting
14.
The device commonly used for triggering a triac is
15.
Which one of the following controls reduces the size of the transformer in a switch mode ac power supply ?
16.
Thyristor is nothing but a
18.
The triac is equivalent to
19.
A UJT is sometimes called a______diode.
20.
Control system that maintains a speed voltage, or other variable within specified limits of a preset level.
21.
What Greek word which means “switch”?
22.
ECG stands for electrocardiography while EEG stands for?
23.
An SCR chopper circuit supplies power to a dc motor , what will be the nature of motor armature current?
24.
When the supply voltage exceeds the breakover voltage of an SCR, it
26.
A feedback control system in which the controlled variable is mechanical position.
27.
The basic difference between a series regulator and a shunt regulator is
28.
When the temperature increases, the intrinsic stand off ratio
29.
To turn off the SCR, which of the following is done?
30.
Turned-off time of a thyristor
31.
The snubber circuit is used in thyristor circuits for
32.
The p-type emitter of a UJT is ______doped.
33.
A freewheeling diode in a phase-controlled rectifier
34.
Which of the following configurations is used for both motoring and regenerative braking?
35.
Which device does not have a gate terminal?
36.
Which device exhibits negative resistance region?
37.
Thyristor is a semiconductor switch which is
39.
Which of the following is a four-layer diode with an anode gate and a cathode gate?
40.
Latching current of an SCR is
41.
The V-I characteristics for a triac in the first and third quadrants are essentially identical to those of in the quotation.
43.
The most suitable device for high frequency inversions in SMPS is
44.
Freewheeling diode at the output of a rectifier allows
45.
What is a solid state equivalent of a gas filled triode?
46.
What is a three terminal device used to control large current to a load?
47.
A single-phase half wave rectifier circuit has a freewheeling diode. The freewheeling diode will conduct only if
48.
As compared to power MOSFET, a BJT has
49.
What is the sensing element of acceleration transducer?
