Physics-
General
Easy
Question
Figure given below shows two identical parallel plate capacitors connected to a battery with switch 
closed. The switch is now opened and the free space between the plate of capacitors is filled with a dielectric of dielectric constant 3. What will be the ratio of total electrostatic energy stored in both capacitors before and after the introduction of the dielectric
- 3 : 1
- 5 : 1
- 3 : 5
- 5 : 3
The correct answer is: 3 : 5
Initially potential difference across both the capacitor is same hence energy of the system is
……(i)
In the second case when key K is opened and dielectric medium is filled between the plates, capacitance of both the capacitors becomes 3C, while potential difference across A is V and potential difference across B is 
hence energy of the system now is
……(ii)
So, 
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