Write short note on e.m.f. devices. - Vidyadip

Question

Write short note on e.m.f. devices.

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Answer

When charges flow through a conductor, a potential difference get established between the two ends of the conductor.
For a steady flow of charges, this potential difference is required to be maintained across the two ends of the conductor.
There is a device that does so by doing work on the charges, thereby maintaining the potential difference. Such a device is called an emf device and it provides the emf E.
The charges move in the conductor due to the energy provided by the emf device. This energy is supplied by the e.m.f. device on account of its work done.
Power cells, batteries, Solar cells, fuel cells, and even generators, are some examples of emf devices.

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