2. Table of Contents:
• What is Electromagnetic Radiation
• Electromagnetic Theory
• Properties of Electromagnetic Radiation
• Electromagnetic Spectrum
3. Electromagnetic Radiation
• Initially electricity and magnetism were considered to be separate forces.
Later in the year 1873, James Clerk Maxwell, the Scottish physicist,
developed a combined theory known as electromagnetism. An
electromagnetic field produces electromagnetic radiation also referred to
as EM radiation. Electromagnetic radiation is a form of energy that is
present all around us and takes various forms like microwaves, television
waves, radio waves, gamma rays, X-rays, etc. In this piece of article, we
will discuss electromagnetic radiation and its properties.
4. What is Electromagnetic Radiation?
• Electromagnetic radiation can be defined as a form of
energy that is produced by the movement of electrically
charged particles travelling through a matter or vacuum or
by oscillating magnetic and electric disturbances. The
magnetic and the electric fields come at 90° to each other,
and the combined waves move perpendicular to both electric
and magnetic oscillating fields occurring during the
disturbance.
5.
6. Electromagnetic Theory
• Magnetism and electricity were once considered as
separate forces. However, in the year 1873, Clerk
Maxwell, a Scottish physicist developed a unified theory
of electromagnetism. Its study deals with how the
electrically charged particles interact among themselves
and with the magnetic field. The main electromagnetic
interactions are provided in the points mentioned below.
7. • Magnetic poles come in pairs that repel and attract
each other, just like electric charges do.
• The force of repulsion or attraction between two
electric charges is inversely proportional to the square
of the distance between the particles.
• An electric field in motion produces a magnetic field.
• A wire with an electric current produces a magnetic
field whose direction depends on the direction of
the electric current
8. Properties of Electromagnetic Radiation
• When electromagnetic radiation occurs, it is released as photons.
These are bundles of light energy or quantized harmonic waves which
travel at the speed of light. Then based on the wavelength of the
electromagnetic spectrum, the energy is grouped into different
categories. These magnetic and electric waves travel perpendicular to
each other and have some characteristics like wavelength, amplitude,
and frequency. Some basic properties of Electromagnetic Radiation
are given in the points mentioned below.
10. • They can travel through empty space. Waves other than
electromagnetic waves have to travel through some substance.
For example, sound waves will need either a solid, liquid or gas
to pass through.
• The speed of light which is 2.99792458 x 108 m/s is always
constant.
• Wavelength is commonly characterized by the symbol ‘λ’. It is
defined as the distance between two most near points in phase
with each other. Hence, two adjacent crests or troughs on a wave
are separated by a distance of a single complete wavelength.
11. Waves and their Characteristics
• Electromagnetic radiation occurs when an atomic
particle, like an electron, is accelerated by an electric
field, causing it to accelerate. Electromagnetic
waves and their characteristics is explained briefly in
the points mentioned below.
