Two conductors P and R have capacities in the ratio 2:3 The conductor P recieves a charge and share it - Physics - Electrostatic Potential And Capacitance

Question

Two conductors P and R have capacities in the ratio 2:3 The
conductor P recieves a charge and share it witth R Compare the
total energy of P and R after sharing with the energy of P before
sharing

Rajnish Singh · Accepted Answer

Let us suppose that P recives the charge q and shares with R than
after sharing charge remains q/2 on both surfaces of P and R
After sharing
Total energy of P and R
Uafter -P = q222C1 = q28C1Uafter -R = q222C1 = q28C2total after = q28C1+q28C2 =q28(12+13) =5q28×6=5q248   
1>now  before totall energy of P  is Uinitially  -P  = q22C1 =q22×2 =q24      
2>dividing both above equation 5q248q24 = 512 =5:12

Two conductors P and R have capacities in the ratio 2:3.The conductor P recieves a charge and share it witth R.Compare the total energy of P and R after sharing with the energy of P before sharing.