InterviewSolution
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InterviewSolution
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The self-inductance of a choke coil is `10mH`. When it is connected with a `10 V DC` source, then the loss of power is `20 "watt"`. When it is connected with `10 "volt" AC` source loss of power is `10"watt"`. The frequency of `AC` source will beA. 80 HzB. 100 HzC. 120 HzD. 220 Hz |
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Answer» Correct Answer - A With DC, power, `P = V^(2)/R` `R=(10)^(2)/20 = 5 Omega` With AC power, `P= (V_(rms)^(2)R)/Z^(2) rArr Z^(2) = ((10^(2) xx 5)/10 = 50 Omega` The impedance, `Z^(2) = R^(2)+4pi^(2)v^(2)L^(2)` `50 = (5)^(2) + 4(3.14)^(2) xx v^(2) xx (10 xx 10^(-3))^(2)` v=80 Hz |
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