Electric fields, (refereed to as e-fields,) provide a structure in space to apply a force to any body with a net charge. Electric fields can be controlled with multiple charges. Batteries are great sources of free charges. The typical setup for studying electric fields is shown below.
The plate connected to the positive side of the bateries get a positive charge. The plate connected to the negative side of the batteries becomes negatively charged. The e-field is defined as the path a positive particle would travel. In this diagram above a positive particle would travel to the plate connected to the negative side of the battery.
The electric field is between the two plates is defined by
electric field [N/C] or [v/m]
distance betweenthe plates [m]
Potential difference acros the two surfaces [v]
As a particle travels from one plate the other the amount of work done is equal to qV.
the particle's net charge, [C]: Coulombs
is the potential difference of the power source, [v]: volts
This means that the energy lost or gained as a charged particle crosses the plates is equal to qV. Because the amounts of energy are so small they are measured in electronVolts, eV's.
If a particle with a charge equal to a single elementaty charge, such as an electron or proton, travels across an electric field made by a battery, then the energy lost of gained equals the (# of elementary charges)x(the battery voltage) = eV's. Energy is lost of the opposite plate is the same sign as the particle and t is gained if the opposite plate is the opposite sign of the particle.
For example: If the plates above are connected to a 12 volt battery, then an electron would gain 12 eV's of energy. A proton would lose 12 eV's of energy.
Example 2: If a particle with a charge equal to 3 elctrons travels between the plates while they are conencted to a 5
volt battery then the particle would gain (3)(5) = 15 eV's of energy.
Another important characteristic of an e-field is the fact that it can also guide charge particles. If we could create the e-field below, charges would travel around the corner.
As it turns out, this is easily done with a conducting wire.
This is because the electric field travels along the outside of the wire to move the charges in a current.