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A series L.R circuit connected with an ac source E = (25 sin 1000 t) V has a power factor of . 2 1 If the source of emf is changed to E = (20 sin 2000 t) V, the new power factor of the circuit will be:

1. 7 1
2. 2 1
3. 5 1
4. 3 1

Correct answer: 5 1

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