Question

Which, of the following is/are the property properties of a monochromatic electromagnetic wave propagating in free space?
a) Electric and magnetic fields will have a phase difference $\frac{\pi }{2}$ .
b) The energy of the wave is distributed equally between electric and magnetic fields.
c) The pressure exerted by the wave is the product of its speed and energy density.
d) The speed of the wave is equal to the ratio of magnetic field to the electric field.

• A. (a) and (c)
• B. Only (b)
• C. (b) and (c)
• D. Only (d)

Answer 1

Answer: (B)

The energy of electromagnetic wave is equally distributed between electric and magnetic field.
Some more properties of electromagnetic waves are as given below,
(i) Electric and magnetic field will have zero phase difference.
(ii) The pressure exerted by electromagnetic wave is the ratio of energy density to the speed of light.
(iii) The speed of wave is equal to the ratio of electric field to the magnetic field.