Two cells of emfs 1.5 V and 2.0 V having internal resistances 0.2`Omega` and 0.3`Omega` respectively are connected in parallel. Calculate the emf and internal resistance of the equivalent cell.

Explanation

For parallel grouping of two cells `epsi_1 = 1.5V , epsi_2 = 2.0 V , r_1 = 0.2 Omega " and " r_2 = 0.3 Omega`
Internal resistance of equivalent cell `r_(eq) = (r_1 r_2)/(r_1 + r_2) = (0.2 xx 0.3)/((0.2 + 0.3)) = 0.12 Omega`
and emf of equivalent cell `epsi_(eq) = (epsi_1 r_2 + epsi_2 r_1)/((r_1 + r_2)) = (1.5 xx 0.3 + 2.0 xx 0.2)/((0.2 + 0.3)) = 1.7V`