Question: 27: The ratio of the magnitude of the magnetic field and electric field intensity of a plane electromagnetic wave in free space of permeability \mu_{0} and permittivity \varepsilon_{0} is (Given that \mathrm{c} is velocity of light in free space
(1) c
(2) \frac{1}{\mathrm{c}}
(3) \frac{\mathrm{c}}{\sqrt{\mu_{0} \varepsilon_{0}}}
(4) \frac{\sqrt{\mu_{0} \varepsilon_{0}}}{\mathrm{c}}
Answer: Option (2)
Explanation:
For a plane electromagnetic wave propagating in free space, the electric field E
and magnetic field B are related by
E = cBwhere c is the speed of light in free space.
Rearranging the above relation, the ratio of the magnetic field to the electric field is
\frac{B}{E} = \frac{1}{c}Thus, the ratio of the magnitude of the magnetic field and electric field intensity of a plane electromagnetic wave in free space is \frac{1}{c}.
Hence, the correct option is (2).