Maxwell had developed a set of equations describing the laws of
electricity and magnetism and using these equations he derived what
is known as the wave equation from which he predicted the existence
of electromagnetic waves* From the wave equation, Maxwell could
calculate the speed of electromagnetic waves in free space and he found
that the theoretical value was very close to the measured value of speed
of light From this, he propounded that light must be an
electromagnetic wave Thus, according to Maxwell, light waves are
associated with changing electric and magnetic fields; changing electric
field produces a time and space varying magnetic field and a changing
magnetic field produces a time and space varying electric field