Now, we know that emf is induced when there is a flow of charge. Since, there is a flow of charge in the cell, battery and generator. Therefore, we can say that am emf can be induced in all the three sources. Therefore, the source of emf is cell, battery and generator.

What do you mean by internal resistance of cell?

Internal resistance refers to the opposition to the flow of current offered by the cells and batteries themselves resulting in the generation of heat. Internal resistance is measured in Ohms. The relationship between internal resistance (r) and emf (e) of cell s given by. e = I (r + R)

What is internal resistance and what are the factors affecting internal resistance?

Greater the conductivity of the electrolyte, lesser is the internal resistance of the cell. That is, internal resistance depends on the nature of the electrolyte. The internal resistance of a cell is inversely proportional to the common area of the electrodes dipping in the electrolyte.

What factors affect internal resistance of a battery?

In practice, the internal resistance of a battery is dependent on its size, state of charge, chemical properties, age, temperature, and the discharge current.