1.
SCR turns OFF from conducting state to blocking on
2.
When the temperature increases, the intrinsic stand off ratio
3.
The triac is equivalent to
4.
An SCR is made of silicon and not germanium because silicon.
5.
The typical turn-off time of an SCR is about
6.
Turn-on and turn-off times of transistor depend on
7.
The value of anode current required to maintain the conduction of an SCR even though the gate signal is removed is called as the
8.
In order to get best results per unit cost, the heat sinks, on which the thyristors are mounted , are made of
9.
What is a solid state equivalent of a gas filled triode?
10.
The three terminals of an SCR are the
11.
Which of the following devices should be used as a switch in a low power switched mode power supply (SMPS) ?
12.
R-C snubber is used in parallel with the thyristor to
13.
A boost-regulator has an input voltage of 5V and the average output voltage of 15 V. The duty cycle is
14.
When SCR starts conducting, then ______losses all control.
15.
dv/dt protection is provided to the SCR by
16.
To turn on the UJT, the forward bias on emitter diode should be______ the peak point voltage.
17.
What is dimensionless parameter of the second-order characteristic equation?
18.
Dc to dc converter or chopper can
19.
The minimum gate current which can turn on SCR is called:
20.
Line regulation is determined by
21.
Current in SCR to turn on transient can be reduced by
22.
A thyristor has its gate current zero. To start conduction the forward voltage must exceed
23.
A UJT is sometimes called a______diode.
24.
Which of the following is NOT a method primarily used for density sensing?
25.
Which equation defines the intrinsic stand off ratio (y) of UJTs?
26.
The di/dt protection for an SCR is achieved through the use of
27.
The terminals of a power MOSFET are called
29.
The V-I characteristics for a triac in the first and third quadrants are essentially identical to those of in the quotation.
30.
When the temperature increases, the inter-base resistance of a UJT
31.
The use of multiphase rectifier in place of one phase rectifier results in
32.
When UJTs is turned on, the resistance between emitter terminal and lower base terminal
33.
After firing an SCR, the gate pulse is removed . The current in the SCR will
34.
An SCR is a member of what family?
35.
In ac motor control, the ratio of voltage-to-frequency is maintained at constant value
36.
An SCR is in conducting state, a reverse voltage is applied between anode and cathode, but it fails to turn off. what could be the reason?
37.
When the firing angle of SCR is increased, its output
39.
The p-type emitter of a UJT is ______doped.
40.
A transduction principle used primarily in optical sensors.
41.
The output voltage in a switching regulator for an input Vin and duty cycle δ is
42.
How many semiconductor layers does a triac have?
43.
Which is the control element in an SCR?
44.
A single-phase half wave rectifier circuit has a freewheeling diode. The freewheeling diode will conduct only if
45.
What region lies between the peak point and valley point of UJT emitter characteristic?
46.
In a self-controlled synchronous motor fed from a variable frequency inverter
47.
An ideal regulated power supply should have
48.
An SCR remains turned on if the anode current is more than
49.
Switching regulators are also called
50.
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
