Evaluate Phase difference between voltage and current:
An inductive coil of reactance 15.7 Ω and resistance 32 Ω is connected in series with a capacitor of reactance 79.5 Ω. The circuit is connected across 500 V AC supply, Find out
1. Current,
2. Phase difference between voltage and current,
3. Magnitude of voltage across the inductive coil, and
4. Total power absorbed.
Solution
Figure for Example
R = 32 Ω, X = XL - XC
= - 63.8 Ω (circuit in capacitive)
Impedance Z = R - jX = 32 - 63.8 j Ω
(a) Current i = v / Z = 500 ∠ 0^{o} / 32 - 63.8 j
= 7 ∠ 63.36o Amp
(b) Angle between V and i
φ = 63.36 (leading)
(c) Impedance of coil, Z_{L} = R + j X_{L} = 32 + j 15.7
| Z_{ L} | = 35.6439 Ω
Voltage across coil = I Z_{L} = 7 × 35.6439
= 249.5075 Volt
(d) Power absorbed = I^{2 }R = 7^{2} × 32 = 1568 watts