Comparison of Emf s of Two Cells #8211; Let l<sub>1</sub> and l<sub>2</sub> be the balancing lengths with the cells E<sub>1</sub> and E<sub>2</sub> respectively, then E<sub>1</sub> = xl<sub>1</sub> and E<sub>2</sub> = xl<sub>2</sub> ⇒ E<sub>1</sub>/E<sub>2</sub> = l<sub>1</sub>/l<sub>2</sub>