Problem

A capacitor of capacitance

C

is charged by a battery of emf

E

and internal resistance

r

. A resistance

2r

is also connected in series with the capacitor. The amount of heat liberated inside the battery by the time capacitor is 50% charged is (a)

\frac{3}{8} E^2 C

(b)

\frac{E^2 C}{6}

(c)

\frac{E^2 C}{12}

(d)

\frac{E^2 C}{24}