The internal resistance of an equivalent cell replacing $n$ cells of internal resistances $r_1, r_2,

Question

The internal resistance of an equivalent cell replacing $n$ cells of internal resistances $r_1, r_2, \ldots, r_n$ connected in parallel is given by:

Professor PC Thomas Classes · Answer

For cells in parallel, the reciprocal of the equivalent internal resistance is the sum of the reciprocals of the individual internal resistances.