Question

The electronvolt is the energy knetic energy gained by an electron when it is accelerated in a potential difference.

I have two questions involving eV

1. Does it mean that inside of the battery there is an electric field and this electric field will accelerate the electron, when the electron pass through it? It mean that in an open circuit there is no knetic energy involved?

2. the reason we say " accelerated in a potential difference" is because the electron need be able to move therefore it will only occur when you have a closed circuit?

Answer 1

1) In a battery, there are two terminals that help in maintaining a constant potential difference and whenever there is potential difference, there is an electric effect so yes electric field does exist inside the battery which drives the electrons.

2) Exactly electrons can be accelerated through a potential difference only when it is a closed circuit, otherwise the free electrons will suffer losses inside the resistor and will not accelerate. Battery provides them energy to accelerate.