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The rms value of alternating current which when passed through a resistor produces heat energy four times that produced by directed current of 2 A through the same resistor in same time isA. 2AB. 4AC. 8AD. 16A |
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Answer» Correct Answer - B `H_(dc)=I_(dc)^(2)Rt=4Rt=W` . . . (1) `H_(ac)=I_(ac)^(2)Rt=4W ` . . . (2) `therefore (4W)/(W)=(I_(ac)^(2)Rt)/(4Rt)` `therefore I_(ac)^(2)=16` `therefore I_(ac)=4A` |
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