Very large values of modulation index (greater than 3.24) lead to___________?

Related Mcqs:

1. Unipolar modulation is generally used in____________?

   A. AC – AC converters B. AC – DC converters C. DC – AC converters D. DC – DC converters...

2. Double edge modulation eliminates certain harmonics when the reference is a__________?

   A. Sine wave B. Square wave C. Triangular wave D. Trapezoidal wave...

3. In bipolar modulation, the carrier is symmetric about zero with amplitude equal to Cm, the PWM output

   A. Zero B. Switches between – 1 / 2 and + 1 / 2 C. Switches between – 1 and + 1 D. Switches between 0 and + 1...

4. A combination of synchronized leading edge and trailing edge modulation has also been used to control a____________?

   A. Boost single – phase power factor converter B. A buck dc – dc converter to reduce ripple in the intermediate dc bus capacitor C. Both A. and B. D. None f these...

5. The function of snubber circuit connected across the SCR is to___________?

   A. Suppress dV / dt. B. Increase dV / dt. C. Decrease dV / dt. D. Decrease di / dt....

6. 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...

7. The output current in PWM DC – DC converters is equal to___________?

   A. Average value of the output inductor current B. Product of an average inductor current and a function of duty ratio C. Either A. or B. D. None of these...

8. In a square – wave operation of 3 phase CSIs, the power values are on for___________?

   A. 60 degree B. 90 degree C. 120 degree D. 150 degree...

9. When a large surge current of very short duration flows through a thyristor then which one of the following device will operate to protect the thyristor ___________?

   A. CB B. Snubber circuit C. Voltage clamping device D. Fast acting current limiting device (FACL fuse)...

10. A PNPN device having two gates is ___________?

    A. Diac B. Triac C. SUS D. BCS...