A coil with inductive reactance 31 Ω and resistance 8 Ω is in series with a capacitor having reactance 25 Ω. The source voltage is 110 V AC. Determine the power factor.
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A coil with inductive reactance 31 Ω and resistance 8 Ω is in series with a capacitor having reactance 25 Ω. The source voltage is 110 V AC. Determine the power factor.

G1 Physics · Accepted Answer

Step 1: For an RLC series circuit, phase angle satisfies cosφ=R/Z, Z=√[R²+(X(L)−X(C))²]. Step 2: Given R=8Ω, X(L)=31Ω and X(C)=25Ω, net reactance is 31−25=6Ω. Step 3: Z=√(8²+6²)=10Ω; cosφ=8/10=0.8. Answer D. Final answer: (D) 0.80.