Condensers of capacities 5F and 10F are connected in parallel in a circuit with a cell of e.m.f. 2V. The capacity of the condenser to be connected in series with parallel combination of the condensers to get 1C charge to flow in the circuit is

Options

A. 0.62 F
B. 0.52 F
C. 1.62 F
D. 0.42 F

Answer

B

Explanation

`C_(p)=C_(1)+C_(2)=5+10=15F`
`C_(S)=(C*C_(p))/(C+C_(p))`
Now," "`Q=C_(S)*V`
`Q=((C*C_(p))/(C+C_(p)))V`
`1=((Cxx15)/(C+15))xx2`
`therefore" "C=0.52F.`