Electromagnetic waves travel at the speed of light through space or a medium. The wavelength and frequency of these waves are inversely related by the formula f*λ = c, where f is frequency, λ is wavelength, and c is the speed of light. For a given medium, the speed of light does not change, so higher frequency waves have shorter wavelengths, and lower frequency waves have longer wavelengths. Electromagnetic fields are present everywhere and invisible to humans. Electric fields are created by voltage differences and magnetic fields are created by electric currents. Both decrease in strength with distance from their source.

1. Naveen Sihag
B-TECH

3. Electromagnetic waves travel through
space at the speed of light , and the
wave length and frequency of an
electromagnetic wave are inversely
related by mathematical formula f*λ =c
or f=cλ
Or
λ=c/f
Since the speed of light in a given
medium does not change ,high frequency

4. ELECTROMAGNETIC FIELDS
 Electric fields are created by differences in
voltage: the higher the voltage the stronger
will be the result & field. Magnetic field are
created when electric current , the stronger
the magnetic field if current does not flow
the strength of the magnetic field will be
constant.
 Electro magnetic field are present every
where in our environment but are invisible
to human .

5.  Electric field arise from  Magnetic field arise
voltage. from current .
 There strength is  There strength is
measured in volts per measured in ampere
meter (V/m). per meter (A/m).
 An electric field can be  Magnetic fields exist as
present even when a soon as device
device is switched off. switched on.
 Field strength  Field strength
decreases with decreases with
distance from the distance from the
source. source.
 Most building  Magnetic fields are not
materials shield attenued in most
electric field to some materials
extend.

9.  Effect of radiation due to
following rays :-
 Alpha rays
 Beta rays
 Gamma rays
 X-rays