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[SOLVED] energy dissipation in a RC circuits with initially charged capacitors

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srimatresri

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in the following ckt, both caps are having different charges, so while charge transfer some charge is dissipated through resistor. how to calculate it.

rc energy.PNG
 

i solved it like this.
correct me if i am wrong
13092011071.jpg
 

Your solution looks long winded.
1. Calculate the voltages in steady state after the switch has been closed. It's just a charge balance problem and doesn't depend on R.
2. Calculate stored energies in initial and final state. The difference is is the dissipated energy.
 

thanks for your suggestion,
can u please solve this
 

thanks for ur suggestion
i solved the other way as u said, here it is
13102011195.jpg

but the question that arose is
why and how energy is dissipated for charge sharing?
 

You can think like this:
Tha placement of the switch can be changed, placing it between a C and the R;
Looking between the two terminals, the series of the two C's is completely equivalent to (indistinguishable from) a single C of value Ceq (0.83... F) initially charged at Vs=V1+V2 (6 V), whose energy is Ceq*Vs^2/2.
In the final condition, all this energy is dissipated.

Regards

Z
 
One more comment:
The rest of the energy in the C's (once steady state is reached) can not be extracted without accessing the node between them.
Regards

Z
 

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