Magnetic Field and Magnetic force / Electromagnetic Spectrum and Electromagnetic Waves


Magnetic field

The space around a magnet or a current-carrying conductor where the magnetic effect can be experienced is called the magnetic field. The magnetic field around a permanent magnet will attract ferromagnetic substances like iron, cobalt etc. The magnetic field is a vector quantity and the SI unit of the magnetic field is tesla or Wb/m2. The magnetic field and the electric field are interrelated, they are the components of the electromagnetic force. The electromagnetic force is one of the fundamental forces of nature.

Generators and motors work on the principle of rotating magnetic fields. In devices like transformers, there is an interaction between the electric field and the magnetic field. The Earth is a large magnet that has its own magnetic field around it. This acts as a shield and protects the earth’s ozone layer from the solar winds.

The magnetic field is represented by the magnetic field lines. It will show the direction of the magnetic force on a north monopole at any given position.

Magnetic force

The attractive or the repulsive force between the poles of the magnet and the moving charged particles is called magnetic force. The magnetic field and magnetic force are related terms. The moving charge experiences a force that is perpendicular to the velocity and the magnetic field.

The force experienced by a moving charge will change depending on the speed, location and direction. The force is described by the electric field and the magnetic field. The electric field will give the component of the force that is independent of the motion of the charges. The magnetic field will give the component of the force that depends on the direction and the velocity of the charge.

The Lorentz force law will describe the force experienced charge at a point. The law says,

F = qE + q(v x B)

F is the force experienced by the charge

q is the charge of the particle

E is the electric field

v is the velocity of the charge

B is the magnetic field

Electromagnetic Spectrum

The electromagnetic waves with different frequencies are covered in the electromagnetic spectrum. Depending on the frequency range the waves are given different names. The radio waves have the least frequency and the gamma rays have the highest frequency. Let us discuss more on the electromagnetic spectrum and electromagnetic waves. The electromagnetic waves have the electric field and magnetic field perpendicular to the direction of propagation. The electromagnetic spectrum includes radio waves, microwaves, infrared rays, visible light, ultraviolet light, x-rays and gamma rays.

These electromagnetic waves with different frequency ranges have different characteristics. These waves have different applications. Electromagnetic waves are differentiated by their properties like wavelength, frequency and the energy of the photon. These waves interact with matter in different ways. The electromagnetic waves do not have a defined boundary. These waves will fade into each other.

The radio waves and microwaves help in communication. The visible light allows us to see all the objects around us. The gamma rays are used for ionization purposes.