In a potentiometer experiment two cells of emf \[{{E}_{1}}and\text{ }{{E}_{2}}\] are used in series and in conjunction and the balancing length is found to be 58 cm of the wire. If the polarity of \[{{E}_{2}}\] is reversed, then the balancing length becomes 29 cm. The ratio \[{{E}_{1}}/{{E}_{2}}\] of the emfs of the two cells is-