Question

A 15 Ω resistor, an 80 mH inductor and a capacitor of capacitance C are connected in series with a 50 Hz ac source. If the source voltage and current in the circuit are in phase, then the value of capacitance is ______

विकल्प

• 100 μF

• 127 μF

• 142 μF

• 160 μF

Answer 1

A 15 Ω resistor, an 80 mH inductor and a capacitor of capacitance C are connected in series with a 50 Hz ac source. If the source voltage and current in the circuit are in phase, then the value of capacitance is 127 μF.

Explanation:

Voltage and current will be in phase when X_C = X_L

Or, 1/ωC = ωL

Or, 1/2πfC = 2πfL

Or, C = 1/4π²f²L

Or, `C = 1/(4 xx (3.14)^2 xx (50)^2 xx 80 xx 10^-3`

C = 127 μF