Electrical Energy Concept and Examples | What is Electrical Energy? – Video & Lesson Transcript | Study.com

Video Transcript

What Is Electrical Energy?

Energy is the ability to do work, where work is done when a force moves an object. We need and we use energy every day, and energy is available in all different forms. Electrical energy is energy that’s stored in charged particles within an electric field. Electric fields are simply areas surrounding 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 the 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 energy, let’s explore electric fields in a bit more detail. Electric fields are like gravitational fields in that both fields are areas surrounding an object that are influenced by the object. A gravitational field surrounds the earth, providing a force that pulls us down.

Likewise, electric fields surround charged sources and exert a force on other charged particles that are within 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 that a positive test charge would move if placed within the field.

Electric fields point in the direction that positive particles would move within them.

Positive objects create electric fields that repel other positive objects; therefore, the arrows are pointing 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’s very important to remember that the direction of the electric field always points in the direction that a positive particle would move within that field.

Electrical Energy Is Potential Energy

Electrical energy is potential energy, which is energy stored in an object due to the object’s position. 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 force of the electric field.

This is much like the potential energy you would have if you rode your bike to the top of the hill. Muscular contractions in your leg muscles provide the energy to move that bike to the top of the hill. The higher you move up the hill, the more potential energy the bike will contain. At the top of the hill, gravity then provides a force that would move the bike back down the hill.

Moving electric field charges against their natural direction adds potential energy to an object.

In a similar manner, 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 exertion of work by an external force would in turn add potential energy to the object, just like working hard to ride your bike up the hill. If the force holding the charge in place is removed, the charged particle will move within the field.

Now, effort is not required to move an object from its high potential energy location to a lower potential energy location. Just like you don’t need energy to coast down a hill, the positive charge doesn’t need energy to move towards the negative source. Both are natural processes. Rather, the stored potential energy due to the position of the charged particle is transformed into kinetic energy, which is energy of motion.

Applications of Electrical Energy

Now that we understand that electrical energy is the ability of a charged particle to move in an electric field, let’s discuss the significance of electrical energy. Electrical energy can be used to move charged particles through a wire from a power plant to our homes and businesses. The movement of a charged particle through a wire is called current, or more commonly, electricity. Electricity is used to work various appliances in our homes.

For example, radios convert electrical energy into sound energy so we can listen to music. Toasters convert electrical energy into thermal energy so we can make toast. Light bulbs convert electrical energy into light energy so we can see what we’re doing in the dark. How neat is that? That’s pretty neat!

Battery terminals create electric potential measured in volts.

A battery is another good example of how electrical energy is used to do work. Batteries have positive and negative terminals that create electric potential – that is, the ability to move a charge. This electric potential is another way of looking at electrical energy and is commonly measured in volts. The greater the voltage, the greater the potential to do work or move a charge. If the terminals are connected by a wire, current, or electricity, moves through the wire. The electricity can then do work such as light a bulb.

Lesson Summary

In review, energy is the ability to do work. Electrical energy is energy stored in a charged particle within an electric field. Electric fields are areas surrounding a charged particle that exert a force on another charged particle within the field. Electrical energy is a type of potential energy, or energy stored in an object due to the position of the object. In the case of electrical energy, the object is the charged particle, and the position is within the electric field.

Another way of looking at electrical energy is electrical potential, which is measured in volts. Electrical energy is used to move charges through wires to create current, or electricity. Electricity is used to do work in our homes and businesses.

Learning Outcomes

At the end of this lesson, you’ll be able to:

• Define energy, work, electrical energy and electric fields and describe how these are related
• Explain how objects move through electric fields
• Discuss why electrical energy is potential energy
• Summarize everyday applications of current, or electricity