Three capacitors of capacitances `3 muF, 9muF` and `18 muF` are connected one in series and another time in parallel. The ratio of equivalent capacitance in the two cases `((C_(s))/(C_(p)))` will be

Options

A. `1 : 15`
B. `15 : 1`
C. `1 : 1`
D. `1 : 3`

Answer

A

Explanation

`(1)/(C_(s)) = (1)/(3) + (1)/(9) + (1)/(18) = (1)/(2) rArr C_(s) = 2muF`
`C_(p) = 3 + 9 + 18 = 30 muF rArr (C_(s))/(C_(p)) = (2)/(30) = (1)/(15)`