In a series LCR circuit with an AC source, R = 300Ω, C = 20 μF, L = 1.0 Henry, ϵrms = 50 V and v = 50/π Hz. Find
(a) The rms current in the circuit and
(b) The rms potential differences across the capacitor, the resistor and the inductor. Note that the sum of the rms potential differences across the three elements is greater than the rms voltage of the source.
Given: resistance R = 300Ω,
Capacitance of capacitor C = 20 μF,
Inductance of inductor L = 1.0 Henry,
Voltage across the circuit ϵrms = 50 V and
Frequency v = 50/π Hz
{a} rms current in the circuit will be
Where Z is impedance in the circuit
Then,
{b} potential difference across the capacitor will be
Potential difference across the resistor will be
Potential difference across the inductor will be
Net sum of all potential drops =
Rms voltage,
Hence, sum of all potential drops > rms potential applied.