Final answer:
In a parallel connection of two cells, the emf of the equivalent source will be the same as the individual cells (lower if the cells have different emfs) while the internal resistance of the equivalent source will be less than the individual resistances.
Step-by-step explanation:
When two cells of emf's E₁ and E₂ and internal resistance r₁ and r₂ respectively, are connected in parallel, the emf (E) and the internal resistance (r) of the equivalent source are given as follows:
- The emf (E) of the equivalent source remains the same as the individual cell. So if the cells have different emfs, the emf of the equivalent source is the lower of the two.
- The internal resistance (r) of the equivalent source can be determined by finding the resistance of resistors in parallel, which is given by the formula: 1/R = 1/r₁ + 1/r₂. Hence, the internal resistance will generally be smaller than the individual resistances.
This is because in parallel combinations, all components experience the same voltage drop and hence the equivalent emf stays same as emf of individual cells, while the effective resistance reduces due to increased potential paths for current.
Learn more about Parallel Connection of Cells