1.
The output voltage in a switching regulator for an input Vin and duty cycle δ is
2.
Turned-on of a thyristor takes place when
3.
A thyristor controlled reactor, the firing angle of thyristor is to be controlled in the range of
5.
When the SCR is OFF, the current in the circuit is
6.
SCR is a rectifier constructed of silicon material. Silicon is chosen because
7.
When an SCR is combined to a switch, it is considered as a switch.
8.
What is an automatic speed control device using the centrifugal force on rotating flyweights as the feedback element?
9.
What is that value of current below which the SCR switches from the conduction state to the forward blocking region under stated conditions?
10.
Triacs can not be used in ac voltage regulator for a
11.
An emitter follower regulator has the following disadvantage :
12.
When the temperature increases, the inter-base resistance of a UJT
13.
When SCR starts conducting, then ______losses all control.
15.
The triac is fundamentally a/an_____with a gate terminal for controlling the turn-on conditions of the bilateral device in either direction.
16.
The minimum gate current which can turn on SCR is called:
17.
Which is four terminal device
18.
Latching current of an SCR is
19.
The terminals of a power MOSFET are called
20.
Static voltage equalization in series connected SCRs is obtained by the use of
21.
Most SCRs can be turned-off by voltage reversal during negative half cycle of the ac supply for
22.
Which device exhibits negative resistance region?
23.
What is the ratio of two exponential functions of time called?
24.
The triac is equivalent to
25.
A resistor connected across the gate and cathode of an SCR
26.
An SCR triggered by a current pulse through its gate can be turned off by
27.
When fed from a fully controlled rectifier, a dc motor, driving an active load can operate in
28.
Which transistor conducts current in both directions when turned on?
29.
An SCR combines the feature of
30.
An SCR is considered to be a semicontrolled device because
31.
Consider the following statements:
A four-layer PNPN device having two gate leads can be turned on by applying a
1. positive current pulse to the cathode gate
2. positive current pulse to the anode gate
3. negative current pulse to the anode gate
4. negative current pulse to tha cathode gate
which of these statement is /are correct
32.
AC voltage regulators are widely used in
33.
In the forward blocking region of a silicon controlled rectifier, the SCR is
34.
Which terminal does not belong to the SCR?
35.
With gate open, if the supply voltage exceeds the breakover voltage of SCR, then SCR will conduct
36.
To turn on the UJT, the forward bias on emitter diode should be______ the peak point voltage.
37.
AC power in a load can be controlled by connecting
38.
A thyristor has its gate current zero. To start conduction the forward voltage must exceed
39.
When the supply voltage exceeds the breakover voltage of an SCR, it
41.
The typical turn-off time of an SCR is about
42.
Carrier frequency gate drive is used for turn-on of a thyristor to reduce.
43.
Conductivity modulation is phenomenon which occurs in
44.
An advantage of cycloconverter is
45.
A triac is equivalent to two SCRs
46.
A diac has how many terminals?
47.
A motor armature supplied through phase controlled SCRs receives a smoother voltage shape at
48.
A thyristors are not made using germanium, because
49.
Which one of the following is a regulated power supply?
50.
ECG stands for electrocardiography while EEG stands for?
