Two cells of emfs \(1~\text{V}\) and \(2~\text{V}\) and internal resistance \(2~\Omega\) and \(1~\Omega,\) respectively connected in parallel, gave a current of \(1~\text{A}\) through an external resistance. If the polarity of one cell is reversed, then value of current through the external resistance will be \(\dfrac{\alpha}{5} ~\text{A} .\) The value of \(\alpha\) is:
1. \(4\)
2. \(3\)
3. \(2\)
4. \(1\)