2.
After firing an SCR, the gate pulse is removed . The current in the SCR will
3.
In a thyristor, di/dt protection is achieved by the use of
4.
A feedback control system in which the controlled variable is mechanical position.
5.
What is the control element in an SCR?
6.
The three terminals of a triac are
7.
The V-I characteristics for a triac in the first and third quadrants are essentially identical to those of in the quotation.
8.
The shunt type regulator is suitable for which of the following?
10.
A diac has how many semiconductor layers?
11.
The supply voltage is generally _____that of breakover voltage in an SCR.
13.
The triac is fundamentally a/an_____with a gate terminal for controlling the turn-on conditions of the bilateral device in either direction.
14.
A freewheeling diode in a phase-controlled rectifier
15.
When an SCR is combined to a switch, it is considered as a switch.
16.
A normally operated SCR has an anode which is _____ with respect to cathode.
17.
What are some areas where GTO is applicable?
18.
For an SCR, dv/dt protection is achieved through the use of
19.
A single-phase half wave rectifier circuit has a freewheeling diode. The freewheeling diode will conduct only if
20.
SCR turns OFF from conducting state to blocking on
21.
Which is suitable for making the variable frequency drives
22.
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
23.
Turned-off time of a thyristor
25.
The triac can be used only in
26.
Which device exhibits negative resistance region?
27.
dv/dt protection is provided to the SCR by
28.
To turn on the UJT, the forward bias on emitter diode should be______ the peak point voltage.
29.
Which is the control element in an SCR?
30.
Latching current of an SCR is
31.
Acceleration transducers are also called
32.
An RC snubber circuit is used to protect a thyristor against:
33.
A thyristors are not made using germanium, because
34.
Dc to dc converter or chopper can
35.
Which is four terminal device
36.
In the SCR structure the gate terminal is located
38.
Triacs can not be used in ac voltage regulator for a
39.
The minimum gate current which can turn on SCR is called:
40.
Which semiconductor power device, out of the following, is not a current triggered device?
41.
Which of the following is the normal way to turn on an SCR?
42.
Which one of the following is the most suitable device for a dc to dc converter?
43.
The triac is equivalent to
44.
Which one of the following is a regulated power supply?
45.
A thyristor controlled reactor, the firing angle of thyristor is to be controlled in the range of
46.
Snubber circuits are used to protect thyristor from which of the following?
47.
What Greek word which means “switch”?
48.
Turn-off time of a thyristor
49.
Most SCRs can be turned-off by voltage reversal during negative half cycle of the ac supply for
50.
Turn-on and turn-off times of transistor depend on
