Current Electricity

In potentiometer experiment, cells of e.m.f. '\(E_1\)' and '\(E_2\)' are connected in series \(\left(E_1>E_2\right)\) the balancing length is \(64 \mathrm{~cm}\) of the wire. If the polarity of \(E_2\) is reversed, the balancing length becomes \(32 \mathrm{~cm}\). The ratio \(\frac{E_1}{E_2}\) is