The maximum power that a combination of two cells of EMF \(E_1\) & \(E_2\) \((E_1>E_2)\) can transfer to an external resistance is \(2~\text{W},\) when they are connected in series. When the EMF's are connected in opposite sense, but in series, this power is \(0.5~\text{W}.\) The ratio of the EMF's is, \((E_1/E_2)\)
1. \(4\)
2. \(3\)
3. \(2\)
4. \(1\)