(a) (i) Three batteries $E_1$, $E_2$ and $E_3$ of emfs and internal resistances ($4\text{ V}$, $2\text{ }\Omega$), ($2\text{ V}$, $4\text{ }\Omega$) and ($6\text{ V}$, $2\text{ }\Omega$) respectively are connected as shown in the figure. Find the values of the currents passing through batteries $E_1$, $E_2$ and $E_3$.