Transformers Archives

11. In case of 3-phase induction motors, plugging means

pulling the motor directly on line without a starter

locking of rotor due to harmonics

starting the motor on load which is more than the rated load

interchanging two supply phases for quick stopping

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12. The purpose of providing iron core in a step-up transformer is

To provide coupling between primary and secondary

To increase the magnitude of mutual flux

To decrease the magnitude of magnetizing current

To provide all above features

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13. The chemical used in breather is

asbestos fiber

silica sand

sodium chloride

silica gel

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14. The noise produced by a transformer is termed as

zoom

hum

ringing

buzz

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class="screen-reader-text">The noise produced by a transformer is termed as

15. The no-load current drawn by transformer is usually what per cent of the full-load current?

0.2 to 0.5 per cent

2 to 5 per cent

12 to 15 per cent

20 to 30 per cent

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usually what per cent of the full-load current?" class="read-more button" href="https://exam.pscnotes.com/mcq/the-no-load-current-drawn-by-transformer-is-usually-what-per-cent-of-the-full-load-current/#more-57798">Detailed Solution

16. The power factor of an induction motor under no-load conditions will be closer to

0.2 lagging

0.2 leading

0.5 leading

unity

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124.1c-6.3-23.7-24.8-42.3-48.3-48.6C458.8 64 288 64 288 64S117.2 64 74.6 75.5c-23.5 6.3-42 24.9-48.3 48.6-11.4 42.9-11.4 132.3-11.4 132.3s0 89.4 11.4 132.3c6.3 23.7 24.8 41.5 48.3 47.8C117.2 448 288 448 288 448s170.8 0 213.4-11.5c23.5-6.3 42-24.2 48.3-47.8 11.4-42.9 11.4-132.3 11.4-132.3s0-89.4-11.4-132.3zm-317.5 213.5V175.2l142.7 81.2-142.7 81.2z"/> Subscribe on YouTube class="screen-reader-text">The power factor of an induction motor under no-load conditions will be closer to