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## Main Question or Discussion Point

I am not sure if I have full understanding of capacitors energy, because I found a contradiction in solving one problem. The problem is: -

If an uncharged capacitor connected to another fully charged capacitor in parallel, what will be the new charge distribution on both capacitors? “Assuming equal capacitance”

I believe we have two rules of respect:-

1- Conservation of charge

2- Conservation of energy

If we assume that C = capacitance, and Vi = initial voltage and Qi=the initial charge on the charged capacitance.

Let the energy before connecting the two capacitance equal to the energy after linking them together:-

0.5*C*Vi^2 = 0.5*(2C)*Vf^2

then: - Vf=Vi/sqrt(2)

Know consider the total charge after linking both capacitors:-

Qt = Ct * Vf= (2C)*Vi/sqrt(2)=C*Vi*sqrt(2)

Which is obviously not equal to C*Vi “the initial charge”.

I am confused which one of these two fundamental concepts I have to base my calculation in, and why it doesn’t work with the other concept.

If an uncharged capacitor connected to another fully charged capacitor in parallel, what will be the new charge distribution on both capacitors? “Assuming equal capacitance”

I believe we have two rules of respect:-

1- Conservation of charge

2- Conservation of energy

If we assume that C = capacitance, and Vi = initial voltage and Qi=the initial charge on the charged capacitance.

Let the energy before connecting the two capacitance equal to the energy after linking them together:-

0.5*C*Vi^2 = 0.5*(2C)*Vf^2

then: - Vf=Vi/sqrt(2)

Know consider the total charge after linking both capacitors:-

Qt = Ct * Vf= (2C)*Vi/sqrt(2)=C*Vi*sqrt(2)

Which is obviously not equal to C*Vi “the initial charge”.

I am confused which one of these two fundamental concepts I have to base my calculation in, and why it doesn’t work with the other concept.