A capacitor of capacitance C is charged to a potential difference V from a cell and then disconnected from it. A charge +Q is now given to its positive plate. The potential difference across the capacitor is now

Options

A. V
B. `V + (Q)/( C)`
C. `V + (Q)/(2 C)`
D. `V -(Q)/( C)`, if `V lt CV`

Answer

C

Explanation

`E=(sigma)/(in_(0))=((Q)/(2)+CV)/(A in_(0)),V=Ed=((Q)/(2)+CV)/((A in_(0))/(d))`
`= ((Q)/(2)+CV)/(C)=V+(Q)/(2C)`.