As shown in figure, if the point C is earthed and the point A is given a potential of 2000 V, then the potential at point B will be :

Options

A. 400V
B. 500V
C. 1000V
D. 1300V

Answer

B

Explanation

`C_(BC)=(10xx10)/(10+10)+10=15muF, C_(AC)=(5xx15)/(5+15)=(75)/(20)muF`.
Charge on capacitor of `5muF=(75)/(20)xx2000=7500muC`
`V_(A)-V_(B)=(7500muC)/(5muF)=1500` volt, `V_(A)=2000`volt, `V_(B)=2000-1500=500` volt.