Q98 / 160 · JIPMER 2014 · Physics

Real power consumption in a circuit is least when it contains.

  • A
    high $R$, low $L$
  • B
    high $R$, high $L$
  • Correct answer
    C
    low $R$, high $L$
  • D
    high $R$, low $C$

Solution

Power consumption $=I_{\text {rms }} V_{\mathrm{rms}} \cos \phi$ where, $\cos \phi$ is power factor. $\cos \phi=\frac{R}{Z}$ For $\cos \phi$ to be minimum, $R$ should be minimum and $Z$ should be higher. So, higher $Z$ (impedance), $L$ (inductance) should be high.

Hence, the correct answer is option: 'C'.

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