Electric Field and Energy

View Assign Share Link Report

Electric Field and Energy

This lesson aligns with Next Generation Science Standards (NGSS) PS3.A

Introduction

Electricity is an essential and more efficient source of energy in our daily lives, from powering our homes and schools to charging our phones, computers, and other electronic devices. But have you ever thoughts about how electricity works in different areas of life and what the different concepts involved are? One such concept is the electric field and energy. An electric field is simply an area in which an electric charge would experience a force if placed within it. In this article, we will learn what electric fields are, how they relate to energy, and some of their practical applications.

What is Electric Field?

To understand the electric field, we have to understand what are electric charges. Electric charges are the particles that have a positive or negative charge. These particles can either attract or repel each other, depending on their charges. When there are charged particles in a specific area, it generates an electric field around them.

An electric field is simply an area in which an electric charge would experience a force if placed within it. In other words, an electric field can be assumed an electric property associated with each point in the space where a charge is present in any form. Generally, an electric field is represented by an arrow to indicate the direction and strength of the force that a charged particle would experience.

Formula

An electric field can be expressed by using the following formula;

E = F/Q

where,

E is the electric field

F is the force

Q is the charge

Unit

Electric field strength is measured in volts per meter or v/m.

Direction

The direction of the field is taken as the direction of the force which is experienced by the positive charge. The electric field lines are radially outwards from the positive charge and radially towards the negative point charge.

Electric fields are created by charged particles, such as electrons or protons. When these particles are stationary, they create a field that is called an electrostatic field. If they are moving, they create a field that is called an electromagnetic field. The electric field can be present around a single charged particle, like an electron or proton, or around multiple charged particles, like the ones found in a wire carrying electricity.

Electric Energy

Electric energy is the energy that is generated due to the movement of charged particles, like electrons. When an electric current flows through a wire, for example, it is the movement of electrons through that wire that creates the electric energy. Generally, electric energy is measured in joules or kilowatt-hours (kWh). A kilowatt-hour is the amount of energy consumed when a 1,000-watt appliance is used for one hour. It is the unit of measurement used on your electricity bill.

Electric energy can be transferred into other forms of energy, such as heat or light. For example, when you turn on a light bulb, the electric energy is converted into light energy, which allows you to see other things in the surrounding. Similarly, when you use an electric heater, the electric energy is converted into heat energy, which is used to warm up the room.

Electric Field and Energy

Electric fields and energy are closely related to each other. When an electric charge moves through an electric field, a force is exerted that can do work. This work can be used to move the charged particle against the force of gravity or to create heat energy. The amount of work done by an electric field is equal to the change in the potential energy of the charged particle.

The potential energy of a charged particle in an electric field is given by the equation:

PE = qV

where PE is the potential energy, q is the charge of the particle, and V is the voltage at the location of the particle. The voltage is a measure of the electric potential difference between two points in an electric field. The electric potential difference is the amount of work that would be required to move a unit charge from one point to another in the field.

The energy stored in an electric field can be calculated using the equation:

E = 1/2CV^2

Where E is the energy stored, C is the capacitance of the capacitor, and V is the voltage across the capacitor. Capacitors are often used in electronic circuits to store energy temporarily and release it when required.

Summary

An electric field can be assumed an electric property associated with each point in the space where a charge is present in any form.
Electric energy is generated due to the movement of charged particles, like electrons.
The amount of work done by an electric field is equal to the change in the potential energy of the charged particle.

Related Worksheets: