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प्रश्न
The power factor of an a.c. circuit is 0.5. What is the phase difference between voltage and current in this circuit ?
उत्तर
\[\text { Power factor of an a . c . circuit } = \cos\varphi = 0 . 5\]
\[\text { where }\]
\[ \varphi = \text { Phase difference between voltage and current }\]
\[ \therefore \varphi = \cos^{- 1} (0 . 5) = 45°\]
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