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Electronics

As the breakdown voltage reached, the DIAC exhibits?

A. Negative resistance characteristics
B. Goes into avalanche condition
C. Voltage drop snaps back
D. All of these

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Electronics

DIAC are specifically designed to trigger______________?

A. TRIAC
B. SCR
C. GTO
D. Only (a) and (b)

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Electronics

In a 3 phase bridge rectifier the ripple frequency is _____________?

A. Equal to the input frequency
B. Twice the input frequency
C. Three times the input frequency
D. Six times the input frequency

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Electronics

The sum of all phase current in a star connected primary winding with no neutral connection is equal to___________?

A. Phase current
B. Three times the phase current
C. Three times the line current
D. Zero at all times

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Electronics

In a load commutated DC – DC chopper, the capacitor has a_____________?

A. Symmetric triangular voltage across itself
B. Symmetric rectangular voltage across itself
C. Symmetric trapezoidal voltage across itself
D. Symmetric sinusoidal voltage across itself

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Electronics

What is an ideal Diode?

A. Unidirectional
B. Bidirectional
C. Fixed voltage polarity
D. Only (a) and (c)

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Electronics

The input current waveform of a bridge controlled rectifier when the load is perfectly filtered is___________?

A. Sine wave
B. Square wave
C. Saw – tooth wave
D. Trapezoidal wave

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Electronics

The IGBT resulted in higher switching speed and lower energy losses. It can be used for___________?

A. Uninterruptible power supplies
B. Induction heating system
C. Constant voltage and frequency power supplies
D. All of these

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Electronics

The advantage of using free – wheeling diode in half controlled bridge converter is that

A. There is always a path for the DC current independent of the AC line
B. There is always a path for the AC current independent of the ac line
C. There is always a path for the DC current dependent of the ac line
D. There is always a path for the AC current independent of the ac line

Categories
Electronics

To detect an over – current fault condition, the most reliable method is to connect a_____________?

A. Current sensor across IGBT
B. Voltage sensor across IGBT
C. Current sensor in series with IGBT
D. Voltage sensor in series with IGBT