The electromagnetic force is a branch of physics that deals with the force existing between two electrically charged particles. It is one of the four fundamental forces. As the name suggests, the electromagnetic force is a combination of electrical and magnetic forces. Depending upon the nature of charges possessed by the two bodies, the electromagnetic force can be attractive or repulsive. When a significant amount of current is made to flow through a conductor, a magnetic field gets developed across the conductor. This process is known as electromagnetism. The electromagnetic force is also known as the Lorentz Force.
1. Party Balloon Trick
When a person rubs a balloon against his/her hair, the electrons get deposited on the outer surface of the balloon causing a static charge to get developed. There exists an interaction between the charge developed on the balloon and the charge present on the wall. This interaction of the charge, called the electromagnetic force, is sufficient enough to stick the balloon to the wall.
Permanent magnetic speakers are used to convert electrical energy into sound energy. It works on the principle of electromagnetism. It consists of a metallic coil that is connected to a permanent magnet. When the current passes through this conducting coil, a magnetic field is developed around it, which intrudes the already existing magnetic field around the permanent magnet. This results in the development of vibrations, which are converted to sound energy. The sound can be further amplified with the help of the conical structure attached to the front of the loudspeaker.
Cathode-ray televisions make use of electromagnetic force to develop images on the screen. The negatively charged particles called electrons are made to pass between the two copper steering coils. The flow of electrons develops a magnetic field, which causes the charged particles to deflect. One of the coils is responsible to control the horizontal motion, while the other coil handles the vertical motion. These deflected electrons hit the screen, causing the phosphorescent coating to glow and produce the image.
4. Chemical Bond
The electromagnetic force plays a key role in forming a chemical bond between two or more elements. Usually, the chemical compounds are formed by ionic bonding, metallic bonding, or covalent bonding. The electromagnetic force acts as a binding force that keeps the atoms of different elements in place.
The electromagnetic force plays a very important role in establishing intermolecular force between the two atoms. This force is solely responsible to bind the two atoms together. Hence, in absence of electromagnetic force, the molecules will not be able to acquire a stable state.
The industrial application of electromagnetic force can be clearly seen in the cranes that are used to collect metallic objects. An electromagnetic crane consists of a large metallic disk wrapped with a wire. The current is supplied through this externally wrapped wire, which accordingly magnetizes or demagnetizes the metallic head. This magnetic field developed due to the flow of current through the conducting wire can be then used to attract and pick the heavy metallic objects.
7. Powder Coating
Powder coating makes use of spraying a coat of charged particles onto the base substrate. The difference in the charges possessed by the base coating and the secondary coating establishes an interaction or an electromagnetic force. The powder particles get attracted to the oppositely charged particles. This helps in increasing the life span of the paint applied to the objects. Electrostatic powder coating is advantageous because it does not make use of any solvents.
Electromagnetic doors are most popular in places that demand a high level of security. A piece of a conductor is attached to the edge of the opening of the door. It is further connected to an electrical circuit via a conducting wire. The current is made to pass through the wire, which is responsible to magnetize and demagnetize the conductor accordingly. When magnetized, the pieces of conductor help close the door with great force. The door only opens when the conductor pieces lose the magnetic energy. The magnetization can be easily controlled by connecting a switch to the current supplying circuit. Hence, it enables the security person-in-charge to control the people entering the premises.