Electromagnetism - Definition, Force, Properties, Applications, FAQs

Electromagnetism is an underlying concept in physics that deals with the interaction between an electric field and a magnetic field. It lays the foundation for modern technology. In this article, we will review what is electromagnetic force, what is an electromagnet and its applications, electromagnetic force examples, and properties, electromagnetic effect, electromagnetic field, electrodynamics, some laws related to electromagnetism and magnetism and electromagnetism.

JEE Main 2025: Physics Formula | Study Materials | High Scoring Topics | Preparation Guide

JEE Main 2025: Syllabus | Sample Papers | Mock Tests | PYQs | Study Plan 100 Days

NEET 2025: Syllabus | High Scoring Topics | PYQs

This Story also Contains

1. Define Electromagnetism
2. What is Electromagnetic Force
3. What is an Electromagnet
4. Key Components of Electromagnetism
5. Bio-Savart Law
6. Ampere's Circuital Law
7. Faraday's Law of Electromagnetism
8. Magnetism and Electromagnetism

Define Electromagnetism

Electromagnetism is a field of physics that focuses on the study of electric fields and magnetic fields and the interaction between them. The electromagnetic force is a manner of physical contact that exists between electrically charged particles. When a conductor crosses the lines of force in a magnetic field, Michael Faraday discovered that an electric current can be generated. With his famous kite-flying experiments in 1752, Benjamin Franklin discovered electricity.

Electromagnetic fields, which are made up of electric and magnetic fields, contain the electromagnetic force, which is responsible for electromagnetic radiation like light. Together with the strong interaction, the weak interaction, and gravitation, it is one of the four fundamental interactions in nature that are often referred to as forces.

Electromagnetism is widely used in modern technology, and electromagnetic theory serves as the foundation for electrical power, engineering, and electronics, including digital technology. The electromagnetic field can be described mathematically in a variety of ways.

What is Electromagnetic Force

Electromagnetic force definition: The force between charged particles is known as the electromagnetic force. At rest, unlike charges are attracted to each other, whereas similar charges repel each other. Magnetic force is created by moving charges. Electromagnetic Force is the name given to these forces when they are combined. All chemical processes that originate from interactions between electrons of nearby atoms are governed by electromagnetic force.

Electromagnetic Force Formula:

$$
\vec{F}=q(\vec{E}+\vec{v} \times \vec{B})
$$

where,

• $\vec{F}$ is the electromagnetic force
• $q$ is the charge of the particle
• $\vec{E}$ is the electric field
• $\vec{v}$ is the velocity of the particle
• $\vec{B}$ is the magnetic field

The electromagnetic force, also characterized as the Lorentz force, is used to define electromagnetic phenomena, which incorporates both electricity and magnetism as distinct manifestations of the same phenomenon. The electromagnetic force is a major factor in defining the interior properties of most everyday items. Except for gravity, the electromagnetic force is responsible for virtually all phenomena encountered in daily life. The movement of these particles carries momentum, which is explained by electromagnetic forces.

Properties of Electromagnetic Force

The electromagnetic force has the following properties:

• It obeys the concept of inverse squares.
• The photon is an electromagnetic force field particle.
• It has the potential to be both seductive and repellent.
• It is both a central and a conservative force.
• It is a force with a long range.
• It has a strength of around 10³⁶ times that of gravity.

Electromagnetic Force Examples

1. Electric motors
2. Generators and Transformers
3. Electromagnets
4. Induction cooking
5. Magnetic attraction and repulsion

What is an Electromagnet

Electromagnet definition: An electromagnet is a magnet whose magnetic field is supplied by an electric current. Wire looped into a coil is used to build electromagnets. The flow of electric current generates a magnetic field that is concentrated in the hole, which functions as the coil's center. When the current is completely off, the magnetic field fades.

An electromagnet is a device that creates electricity to generate a magnetic field. The electromagnet was discovered in 1825 by British electrical engineer William Sturgeon, a former soldier who began dabbling in the sciences at the age of 37.

Applications of Electromagnets

Television

In television, electromagnetism is quite significant. Electromagnets produce the electron beam, which scans the image area. Similarly to how a monochromatic tube scans the screen in a television, the electromagnetic deflection brace deflects or bends the beams.

Speaker

Electrical energy is converted into mechanical energy by speakers (motion). Mechanical energy compresses air and transforms motion into sound energy or sound pressure level (SPL). A magnetic field is generated when an electric current is passed through a coil of wire.

An electromagnet is put in front of a permanent magnet inside the speaker. An electromagnet is moveable, whereas the permanent magnet is set in place. The direction of the electromagnet's magnetic field is rapidly modified when pulses of electricity run through its coil. This means it is attracted to and repulsed by the permanent magnet, which vibrates back and forth. The electromagnet is connected to a flexible cone composed of paper or plastic, which amplifies the vibrations and pumps sound waves into the surrounding air toward our ears.

Magnetic levitation trains

Magnetic levitation is a technique for suspending an object using just magnetic fields as a support. Two sets of magnets are used in magnetic levitation trains, one to repel and push the vehicle off the track, and the other to propel the floating train forward at high speeds without friction. There are no moving parts in this technique. The train moves along a magnetic guideway that uses basic magnet principles to control the train's stability and speed.

Medical system:

Electromagnetic fields are being used in modern medical devices such as cancer hyperthermia treatments, implants, and magnetic resonance imaging (MRI). Electromagnetism-based sophisticated technology can scan even minute aspects of the human body.

Key Components of Electromagnetism

Electromagnetic Field

Accelerating electric charges creates a classical electromagnetic field, which is the classical equivalent to the quantized electromagnetic field tensor in quantum electrodynamics and is described by classical electrodynamics. The fundamental SI unit is the ampere, which is part of a system of electrical units based mostly on the magnetic characteristics of electric currents.

Electromagnetic Effect

The influence of electric and magnetic fields on diverse materials is known as the electromagnetic effect. Water, for illustration, is dipolar but partially aligned when it comes into contact with an electric field and is diamagnetic.

Electrodynamics

The branch of physics is concerned with the effects of electric currents interacting with magnets, with other currents, or with themselves.

Principles of Electromagnetics

The electromotive force induced in the loop due to changing magnetic flux is equal to the rate of change of the magnetic flux threading loop, as per Faraday's Principle of Electromagnetic Induction. Moving a bar magnet in and out of a coil of wire can modify the magnetic flux threading it.

Bio-Savart Law

The Bio-Savart law states that the magnetic field produced by the current element at a given point is directly proportional to the current, the length of the segment, and the sine of the angle between the line element and the one that connects the line to the point.

$$
d \vec{B}=\frac{\mu_0}{4 \pi} \frac{I d \vec{l} \times \vec{r}}{r^3}
$$

where,

• $d \vec{B}$ is the magnetic field produced by the current element
• $\mu_0$ is the permeability of free space
• $I$ is the current flowing through the conductor
• $d \vec{l}$ is the length of the current element
• $\vec{r}$ is the position vector
• $r$ is the magnitude of $\vec{r}$.

Ampere's Circuital Law

Ampere's circuital law states that the line integral of the magnetic field around a closed loop is directionally proportional to the total current passing through the closed loop.

$$
\oint_{\mathcal{C}} \vec{B} \cdot d \vec{l}=\mu_0 I_{\mathrm{enc}}
$$

where,

• $\oint_{\mathcal{C}} \vec{B} \cdot d \vec{l}$ is the the line integral of the magnetic field
• $\mu_0$ is the permeability of free space
• $I_{\text {enc }}$ is the total current enclosed by the path

Faraday's Law of Electromagnetism

Faraday's law states that the induced EMF in a closed loop is directly proportional to the rate of change of magnetic flux passing through the close.d loop

$$
\mathcal{E}=-\frac{d \Phi_B}{d t}
$$

where,

• $\mathcal{E}$ is the induced EMF
• $\Phi_B$ is the magnetic flux through the loop
• $\frac{d \Phi_B}{d t}$ is the rate of change of magnetic flux

Magnetism and Electromagnetism

Electromagnetism is the science of charge and the forces and fields that accompany it. Electromagnetism encompasses the following: electricity and magnetism. For a long time, electricity and magnetism were considered to be two different forces.

Subparts of Magnetism

Magnetic Force

The attraction or repulsion that emerges between electrically charged particles as a result of their motion is known as magnetic force. It is the fundamental force that causes effects like the activity of electric motors and the attraction of magnets to iron.

Electromagnetic Repulsion Force

The electromagnetic force, like gravity, is an infinite-range attracting force that influences everything in the cosmos. It is also a repulsive force that acts between charged particles.

NCERT Physics Notes:

• NCERT Exemplar Solutions for All Subjects
• NCERT Notes For All Subjects
• NCERT Solutions for All Subjects