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MHT CET 2026 (12 May, Shift 1) · Power, Power Factor & Wattless Current

Power, Power Factor & Wattless Current question from MHT CET 2026 (12 May, Shift 1)

Q8MHT CET 2026 · 12 MAY · SHIFT 1Medium

Power, Power Factor & Wattless Current

An e.m.f. e=E0cos⁡ωte = E_0 \cos\omega t is applied to a circuit containing L, C and R in series where XL=4RX_L = 4R and XC=RX_C = R. The average power dissipated in the circuit is

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Answer: (a)

  1. XL−XC=4R−R=3RX_L - X_C = 4R - R = 3R, so Z=R2+9R2=10RZ = \sqrt{R^2 + 9R^2} = \sqrt{10}R.
  2. P=Erms2RZ2P = \frac{E_{rms}^2R}{Z^2} with Erms2=E022E_{rms}^2 = \frac{E_0^2}{2}.
  3. P=E022⋅R10R2=E0220RP = \frac{E_0^2}{2} \cdot \frac{R}{10R^2} = \frac{E_0^2}{20R}.
  4. So the answer is (a) E0220R\frac{E_0^2}{20R}.
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