Question

Net capacitance of three identical capacitors in series is `1 muF`. What will be their net capacitance in parallel ? Find the ratio of energy stored in two configurations if they are connected to the same source.

Answer 1

Correct Answer - `9 muF ; 1 : 9`
Let `C` be the capacity each condenser,
` (1)/(C_(s)) = (1)/(C ) + (1)/(C ) +(1)/(C ) = (3)/(C ) = 1 muF :. C = 3 muF`
`C_(p) = C_(1) + C_(2) + C_(3) = 3 C = 3xx3 = 9 muF`
Let `V` be the `p.d` of same source.
`u_(s) = (1)/(2) C_(s) V^(2)` and `u_(p) = (1)/(2) C_(p) V^(2)`
`:. (u_(s))/(u_(p)) = (C_(s))/(C_(p)) = (C//3)/(3C) = (1)/(9)`