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Assertion : An electric motor will have ...

Assertion : An electric motor will have maximum efficiency when back emf becomes equal to half of applied emf.
Reason : Efficiency of electric motor depends only on magnitude of back emf.

A

A

B

B

C

C

D

D

Text Solution

Verified by Experts

The correct Answer is:
C
From the knowledge of theory, assertion is true but the reason is false.
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PRADEEP-ELECTROMAGNETIC INDUCTION & ALTERNATING CURRENT-Exercise
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  9. Assertion : A glowing bulb becomes dim when an iron bar is put in the ...

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  10. Assertion : In series LCR resonance circuit, the impedance is equal to...

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  12. Statement-1 : When a magnet is made to fall freely through a closed co...

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  13. Statement-1 : When we cousider mutual induction of two coils, their se...

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  14. Statement-1 : In a given situation, the direction of induced current g...

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  15. Statement-1 : An inductor cannot have zero resistance. Statement-2 :...

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  16. Statement-1 : A parallel resonance circuit is called a rejector circui...

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  17. Statement-1 : In 220 V , 50 hz a.c. wall plug. Peak value of alternati...

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  18. Statement-1 : A step up transformer can also be used as a step down tr...

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  19. Statement-1 : The number of turns in secondary coil of a transformer i...

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