why does current depend on voltage?

Question

We know that current means flow of electrons. But according to ohm's law, the flow of electrons need an e.m.f (otherwise called as voltage or potential or potential difference) to flow in an exact direction. And also the source of e.m.f is nothing but the electric field or battery. Hence we understood that current depends on another current indirectly. Here my question is, How could an electric field as an original source provides current without another battery's e.m.f? Please give reason.

Answer 1

An electric field needs SOME source.

It doesn't have to be a battery,

it could be some collection of trapped charges.



For instance you could load a capacitor in a DC circuit,

and if you then you switch the battery out of the circuit,

but create a "short" between the capacitor plates,

the capacitor plates will cause electrons to flow

from one plate to the other till they equilibrate.



Yes - there was a battery involved in creating this situation -

there's no battery in an AC generator, but as I said before,

an electric field cannot be an "original" source.

Answer 2

please take an example of a battery in a circuit,

Battery is having charges stored in it

if you connect a load on battery

the charge will release from one terminal to other to load

So current is not depend upon another current it depend only charges stored, nothing but our battery

Answer 3

Other energy sources, such as heat or light causing a flow of EMF, or a moving magnet inducing emf, or excitation of a crystal (piezoelectric effect).

Answer 4

u should better ask ohm

Answer 5

TO OVERCOME THE CIRCUIT RESISTANCE.