The student is expected to identify examples of electric and magnetic forces in everyday life AND investigate and describe the relationship between electric and magnetic fields in applications such as generators, motors, and transformers.
Every charge creates a disturbance around it. This disturbance is an electric field. An electric field exerts a force on a charged particle.
Stationary electric charges produce only electric forces. Moving electric charges, a current, produce both electric and magnetic forces. A magnetic field only exerts a force on a charged particle if that particle is moving.
An electric current creates a magnetic field, and a changing magnetic field creates an electric current. As the amount of current flowing increases, the size of the magnetic field also increases. Motors and generators make use of this phenomenon.
Electric and magnetic fields are perpendicular to each other.
Electric motors, electric generators and transformers use the interaction between magnetic fields and current-carrying conductors. Motors convert electrical energy into mechanical energy. Generators convert different types of energy into electric energy. Transformers transfer electrical energy from one circuit to another.
Examples of electric and magnetic forces in everyday life include the compass, audio speakers, computer hard drives and the process of applying ink in a copy machine.
Electric Field Forces
Every charge creates a disturbance around it. This disturbance is an electric field. An electric field exerts a force on a charged particle. There are two kinds of electric charges, based on their moving status. The first is a stationary electric charge, and the other is a moving electric charge.
Stationary Electric Charges
Stationary electric charges produce only electric forces. Static electricity is the accumulation of electrical charges on the surface of an object. There are electric fields surrounding the stationary electric charges. In addition, if other electric charges come into the fields, they will experience electric forces.
Moving Electric Charges
Michael Faraday introduced the concept of the electric field, which is a very useful and fundamental concept in physics. The motion of the electric charge plays a vital role in the physical process. Moving electrical charges, such as electric currents, produce both electric and magnetic forces. A magnetic field only exerts a force on a charged particle if that particle is moving. Electricity and magnetism are fundamentally related to one another. This relationship is known as electromagnetism. Moving electric charges (electric current) produce a magnetic field. This means that an electric current produces both an electric field and a magnetic field.
Electric and Magnetic Forces in Our Lives
Electric and magnetic forces can be generated by moving electric charges. We see versatile examples of electric and magnetic fields and forces in our daily life. An electric current creates a magnetic field, and a changing magnetic field creates an electric current. As the amount of current flow increases, the size of the magnetic field also increases.
Electromagnet: An electromagnet is a temporary magnet where the magnetic field is produced by an electric current. The current is the result of moving electric charges. When the current is on, the magnetic force appears. If the electric charges stop moving, the current is off and thus the magnetic property vanishes.
Motors, Generators, and Transformers: Motors and generators make use of this phenomenon. Motors convert electrical energy into mechanical energy. Generators convert mechanical energy into electric energy. Electric motors, electric generators, and transformers use the interaction between magnetic fields and current-carrying conductors. Almost all forces in everyday life are generated by fundamental electromagnetic forces. Some chemical reactions require electromagnetic radiation to break the bonds between molecules.
Transformers are instruments that change the amount of voltage and current from one circuit to another. For example, a transformer is used to raise the voltage of the electricity generated at a power plant to the high levels needed to transmit the electricity efficiently. Other transformers reduce the voltage at the locations where the electricity is used. Many household devices contain transformers to raise or lower house-current voltage as needed. Television sets and stereo equipment, for example, require high voltages; doorbells and thermostats, low voltages. A transformer consists of two coils, one connected to the input, and one connected to the output which can convert voltage up or down, depending on the number of windings on each coil.
Other Examples of Electromagnetic Forces: When you drive your vehicle on the highway, the friction between the tires and the road is an electromagnetic force. A compass, audio speaker, computer hard drive, and copy machine applying ink are all examples of electromagnetic forces. Specifically, when you use the copy machine, the electro-photography uses a high voltage charge to power the cylindrical drum electro-statically.