Question

An A.c circuit consist of 3uf capacitor and 500ohm resistor in series. If the current voltage applied is 12v and frequency 50Hz. Calculate 1. Current through the circuit 2. Voltage accross the capacitor 3 phase angle 4. Average power supplied 5. Power factor

Answer 1

Xc = 1/W*C = 1/314.2*3*10^-6 = 1061 Ohms

Z = R-jXc = 500 -j1061 = 1173[-64.8o].

1. I = V/Z=12/1173[-64.8o]=0.01023[64.8]

2. Vc= I * Xc = 0.01023[64.8]*1061[-90o]= 10.85 Amps.[-25.2o]

3. A = -25.2o

4. P = I^2*R = (0.01023)^2 * 500= 0.0523 W.

5. Pf = cosA = cos(-64.8) = 0.426