Electrostatics Question 522
Question: Two identical capacitors are joined in parallel, charged to a potential V and then separated and then connected in series $ i.e. $ the positive plate of one is connected to negative of the other [NCERT 1972, 73, 82; KCET 1993]
Options:
A) The charges on the free plates connected together are destroyed
B) The charges on the free plates are enhanced
C) The energy stored in the system increases
D) The potential difference in the free plates becomes $ 2V $
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Answer:
Correct Answer: D
Solution:
$ Q _{1}=CV $ and $ Q _{2}=CV $
Applying charge conservation $ CV _{1}+CV _{2}=Q _{1}+Q _{2} $
$ CV _{1}+CV _{2}=2CV $
therefore $ V _{1}+V _{2}=2V $