# How Coulomb's Law relates to generators? (voltage)

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1. Apr 14, 2015

### Celina

1. The problem statement, all variables and given/known data
In science class, we are supposed to explain how a generator works and functions. However, we have to incorporate coulomb's law in our explanation.

2. Relevant equations
F=kQ1Q2/r^2<-- coulomb's law

3. The attempt at a solution
How I understood it was that a generator consists of a permanent magnet and a solenoid. The solenoid is spinning, which causes the magnetic flux to constantly change. This will cause electromagnetic induction to occur, which generates electromotive force or voltage in the solenoid. Electromotive force is the measurement of energy that causes current to flow in a circuit. It can also be seen as pressure on the electrons, or a “push”. In a generator, when voltage is induced in the solenoid, a difference of electrical potential energy will occur. The force between these two charges can be calculated by Coulombs law, which states that opposite charges attract while similar charges repel. The greater the electrical difference, the greater the force that’s generated. Thus, this will cause the electrons to move in a certain way and it will create current.

is that train of thought correct? I'm not so sure if it is scientifically correct. Please help. Thanks so much!

2. Apr 15, 2015

### Simon Bridge

It seems you are expected to explain the generation of electricity in terms of the forces between charges. That would be an unusual approach. Do you have the exact wording of the problem?

The magnetic flux of the permanent magnet does not change.
How does electromagnetic induction occur? (Electromagnetic induction means much the same as generating electricity - so you are begging the question here)
You mention a force between "these two charges" but have only introduced one charge.
The statement of coulombs law is incomplete.

You reasoning seems to be that turning a solenoid results in an induced voltage acorss the solenoid and that causes a current via coulombs law - is that correct?