The Electric Field
When a charge Q is affected by an electrostatic force, there is an electric field.
The following formula shows the relation between them.
From the formula, we can see that the unit of the electric field is: Newton / coulomb (in the MKS system)
The Newton is the unit of force and the Coulomb is the unit of the electric charge.
Note:
- Coulomb = electric charge of 6.28 x 1018 electrons.
- 1 Ampere = 1 coulomb / second
If at some point the electric field is known, we can find the electrostatic force on a charge Q at that point.
We can obtain the following by solving the above formula:
Electric Field lines of Force
An electric field can be represented as lines of force (they don't really exist). They are useful to understand how the electric field works. See the diagram below.
The lines of force show at each point the direction that the electric field (E) has.
These lines never intersect with each other, and when they are close it means that the electric field is more intense.
However, we must take into account that for a given electric field, the number of lines of force is the same.
The lines of force of an electric field always start in the positive charge and end up in the negative charge. See chart
