Page 394 - Basic Electrical Engineering

Voltage across the capacitor,

Substituting values

The students should note that a very high voltage of 3925 V is appearing
across the capacitor while the supply voltage is only 100 V.

Thus, the voltage multiplication across the capacitor as also across the
inductor is 39.25 times at resonance.

Example 3.35 A resistor, a variable iron-core inductor, and a capacitor are

connected across a 230 V, 50 Hz supply. By varying the position of the iron
core inside the inductor coil, its inductance is changed. Maximum current of

1.5 A was obtained in the circuit by changing the inductance of the coil. At
that time the voltage across the capacitor was measured as 600 V. Calculate
the values of circuit parameters.

Solution:

We know that the maximum current flows at resonance when X = X and Z
L
C
= R