A capacitor with stored energy 4 J is connected with an identical capacitor with no electric field in between. Find the total energy stored in the two capacitors.

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Solution

The energy of a charged capacitor is given by U = Q/2C
After the two are connected there will be Q/2 charge on each and hence the energy will
be
U’ = 2 × (Q/2)²/2C= U/2 = 2.0 J

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A capacitor with stored energy 4 J is connected with an identical capacitor with no electric field in between. Find the total energy stored in the two capacitors.

The energy of a charged capacitor is given by U = Q/2C After the two are connected there will be Q/2 charge on each and hence the energy will be U’ = 2 × (Q/2)²/2C= U/2 = 2.0 J

The energy of a charged capacitor is given by U = Q/2C
After the two are connected there will be Q/2 charge on each and hence the energy will
be
U’ = 2 × (Q/2)²/2C= U/2 = 2.0 J