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# Test: Gating Circuits

## 10 Questions MCQ Test Power Electronics | Test: Gating Circuits

Description
This mock test of Test: Gating Circuits for Electrical Engineering (EE) helps you for every Electrical Engineering (EE) entrance exam. This contains 10 Multiple Choice Questions for Electrical Engineering (EE) Test: Gating Circuits (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Gating Circuits quiz give you a good mix of easy questions and tough questions. Electrical Engineering (EE) students definitely take this Test: Gating Circuits exercise for a better result in the exam. You can find other Test: Gating Circuits extra questions, long questions & short questions for Electrical Engineering (EE) on EduRev as well by searching above.
QUESTION: 1

### If the RC firing circuit used for firing an SCR is to be used to fire a TRIAC then

Solution:

The TRIAC is a bidirectional SCR, hence it will need gating in both the directions. This can be achieved by replacing the diode by a DIAC (bidirectional diode).

QUESTION: 2

### In the thyristor gating circuit, the supply to the pulse amplifier is provided by the

Solution:

Isolation transformer provides the supply to the amplifier and also provides the necessary isolation for the load and triggering circuit.

QUESTION: 3

### In the thyristor gating circuit, the ZCD is used to

Solution:

It is used to convert the AC synchronizing input voltage into ramp voltage & synchronizes it with the zero crossing of the AC supply.

QUESTION: 4

The firing-angle delay is

Solution:

If Ec is lowered the firing angle decreases & vice-verse.

QUESTION: 5

The pulse gating is not suitable of

Solution:

It is not suitable of RL load because initiation of SCR conduction is not well defined in these types of loads.

QUESTION: 6

In case of a cosine firing scheme, __________ is used to get a cosine wave

Solution:

The Sync. Transformer is connected to a integrator to obtain a cosine-wave.

QUESTION: 7

If the gating circuits generator negative pulses, then those can be removed by using

Solution:

The clippers can be used to clip the negative part

QUESTION: 8

The improved version of the UJT oscillator triggering circuit is the

Solution:

The ramp & pedal triggering is the improved version of the UJT oscillator triggering circuit.

QUESTION: 9

RB1 = 3 kΩ & RB2 = 6 kΩ. Find the intrinsic stand-off ratio (η) of the UJT.

Solution:

η = RB1/(RB1+RB1).

QUESTION: 10

The decaying factor in the wave shape of the output pulses from the pulse transformer is its

Solution:

L is the decaying factor in the waveform which emerge from the PT.