Question

Standard automobile batteries have six lead-acid cells in series, creating a total emf of 12.0 V. What is the emf of an individual lead-acid cell?

Short answer

The emf of an individual lead-acid cell is 2 V.

Step-by-step solution

Principle and formula

Assume emf of individual lead acid cell is . Since, there is series combination of cell which makes battery. Thus, the net emf of a battery is given as,

E = e + e + e + e + e+ e

= 6E

Calculation of each cell

When cells are connected in series, the resultant EMF is the algebraic sum of EMF of individual cells. Therefore, here the EMF of individual Lead acid cell is

$$\begin{gathered} \mathrm{E}=\frac{12\mathrm{V}}{6} \\ =2\mathrm{V} \end{gathered}$$

However actual EMF is 2 V, slightly greater than the value obtained.