Two parallel plate capacitors are identical, except that one of them is empty and the other contains a material with a dielectric constant of 4.2 in the space between the plates. The empty capacitor is connected between the terminals of an ac generator that has a fixed frequency and rms voltage. The generator delivers a current of 0.24 A. What current does the generator deliver after the other capacitor is connected in parallel with the first one?

Answer 1

Xc = 1/(2pi*F*C).

When an identical capacitor is placed in
parallel, the capacitance doubles and the reactance(Xc) is 1/2. Therefore, the current is doubled:

I = 2 * 0.24 = 0.48A.