What is the relationship between intensity and amplitude of a wave?

What is the relation between the intensity and amplitude of a wave ?

Compare width of slits with the intensity and hence amplitude of the waves.

Write the relationship between amplitudes of electric and magnetic fields in free space for e.m. wave.

The amplitude of the electric field component of an electromagnetic wave is increased from E to 4 E. What is the corresponding change in the intensity of the wave ?

The ratio of amplitude of two waves is 2:3 . What is the ration of intensities of these waves?

The ratio of amplitude of two waves is 2:3. What is the ratio of intensities of these waves?

What are the main difference between amplitude modulated and frequency modulated waves?