Question

A capacitor of capacitance C₁ =1.0 μF carrying initially a voltage V = 300 V is connected in parallel with an uncharged capacitor of capacitance C₂ = 2.0 μF. Find the increment of the electric energy of this system by the moment equilibrium is reached. Explain the result obtained.

Answer 1

Charge contained in the capacitor of capacitance C₁ is q = C₁ φ and the energy, stored in it :

Now, when the capacitors are connected in parallel, equivalent capacitance of the system, C = C₁ + C₂ and hence, energy stored in the system :

 

as charge remains conserved during the process. 

So, increment in the energy,