This lesson defines electrical energy and explores its role as a form of potential energy. It also offers an explanation of how it works within electric fields and provides examples of its applications.
What is electric energy?
The electrical energy definition Energy is the ability to do work, where work is done when a force moves an object. We need and use energy every day, and energy is available in all different forms. Electric power is energy that is stored in charged particles within an electric field. Electric fields are simply areas that surround a charged particle. In other words, charged particles create electric fields that exert force on other charged particles within the field. The electric field applies force to the charged particle, causing it to move, in other words, to do work.
What are electric fields?
Well, what are these electric fields? To better understand electrical power, let’s explore electrical fields in a little more detail. Electric fields are like gravitational fields in which both fields are areas surrounding an object that are influenced by the object. A gravitational field surrounds the earth, providing a force that pushes us down.
In the same way, electric fields surround charged sources and exert a force on other charged particles that are inside the field. Have you ever heard the expression ‘opposites attract’? This certainly applies to electric fields. The image below shows electric fields surrounding both positive and negative sources. The arrows you see illustrate the direction in which a positive test load would move if placed within the field.
Positive objects create electric fields that repel other positive objects; therefore, the arrows point away from the positive source. Negative sources create electric fields that attract positive objects; therefore, the arrows you see are directed towards the negative source. It is very important to remember that the direction of the electric field always points in the direction in which a positive particle would move within that field.
Electric power is potential energy
Electric energy is potential energy, which is the energy stored in an object due to the position of the object. Well, in terms of electrical energy, the object is the charged particle, and the position is the location of that charged particle within the electric field. The charged particle will have the potential to move, or to do work, due to the strength of the electric field.
This is very similar to the potential energy you would have if you drove your bike to the top of the hill. Muscle contractions in the leg muscles provide the energy to move that bike to the top of the hill. The higher you move uphill, the more potential energy the bike will contain. At the top of the hill, gravity provides a force that would move the bicycle down the hill.
Similarly, to move a charge in an electric field against its natural direction of motion requires effort. For example, an external force is needed to move a positive test charge away from a negative source. The effort of work by an external force in turn would add potential energy to the object, as well as work hard to ride your bike uphill. If the force that holds the charge in place is removed, the charged particle will move within the field.