In the figure a potential of `+ 1200 V` is given to point `A` and point `B` is earthed, what is the potential at the point `P` ?

Options

A. `100 V`
B. `200 V`
C. `400 V`
D. `600V`

Answer

C

Explanation

Given circuit can be reduced as follows

In series combination charge on each capacitor remains same. So using `Q = CV`
`rArr C_(1)V_(1) = C_(2)V_(2) rArr 3 (1200 - V_(p)) = 6 (V_(p) - V_(B))`
`rArr 1200 -V_(p) = 2V_(p) ( :' V_(B) = 0)`
`rArr 3V_(p) = 1200 rArr V_(p) = 400` volt