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NEET 2016 (Phase 2) · Power, Power Factor & Wattless Current

Power, Power Factor & Wattless Current question from NEET 2016 (Phase 2)

Q66NEET 2016 · PHASE 2Easy

Power, Power Factor & Wattless Current

The potential differences across the resistance, capacitance and inductance are 80 V, 40 V and 100 V respectively in an L-C-R circuit. The power factor of this circuit is

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Answer: (c)

V_R = 80 VV_L − V_C = 60 VV = 100 Vφ
  1. Net voltage V=VR2+(VL−VC)2V = \sqrt{V_R^2 + (V_L - V_C)^2}.
  2. V=802+(100−40)2=6400+3600=100 VV = \sqrt{80^2 + (100 - 40)^2} = \sqrt{6400 + 3600} = 100\text{ V}.
  3. Power factor cos⁡ϕ=VRV=80100=0.8\cos\phi = \frac{V_R}{V} = \frac{80}{100} = 0.8.
  4. So the answer is (c) 0.8.
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