MCQ
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
- ✓$0.8$
- B$1$
- C$0.4$
- D$0.5$
✓
Answer
Correct option: A.
$0.8$
a
$\text { Here, } V_{R}=80\, \mathrm{V}, V_{c}=40\, \mathrm{V}, V_{L}=100 \,\mathrm{V}$
$\text { Here, } V_{R}=80\, \mathrm{V}, V_{c}=40\, \mathrm{V}, V_{L}=100 \,\mathrm{V}$
Power factor, $\cos \phi=\frac{R}{Z}$
${=\frac{V_{R}}{V}=\frac{V_{R}}{\sqrt{V_{R}^{2}+\left(V_{L}-V_{C}\right)^{2}}}}$
${=\frac{80}{\sqrt{(80)^{2}+(100-40)^{2}}}=\frac{80}{100}=0.8}$
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