LC circuit consists of a 20.0 mH inductor and a 0.200 µF capacitor. If the maximum instantaneous current is 0.100 A, what is the greatest potential difference across the capacitor?

Given Information:  

Inductance = L = 20 mH

Capacitance = C = 0.200 µF

Current = I = 0.100 A

Required Information:  

Potential difference = V = ?

Potential difference = 31.62 V

Explanation:

The energy stored in the electric field is given by

Ue = ½CV²

The energy stored in the magnetic field is given by

Um = ½LI²

From the principle of conservation of energy,

Ue = Um

½CV² = ½LI²

CV² = LI²

V² = LI²/C

V = √LI²/C

V = √(20x10⁻³*0.100²)/0.200x10⁻⁶

V = 31.62 V