Question

How is the speed of em-waves in vacuum determined by the electric and magnetic fields?

Answer 1

The speed of electromagnetic waves in vacuum is calculated using the ratio of maximum values of electric and magnetic fields.

• speed,v= $\frac{E_{0} }{B_{0} }$

• $E_{0}$ is the maximum value of electric field
• $B_{0}$ is the maximum value of magnetic field
• Vibration of charges creates electromagnetic waves. So an em wave contains electric and magnetic components.
• By absorption and re emission of the wave by the atoms of the material, energy transportation is carried out.