Question

The ozone layer absorbs radiation of wavelength
\[\begin{align}
  & \text{A}\text{. less than }3\times {{10}^{-7}}m \\
 & \text{B}\text{. more than }3\times {{10}^{-7}}m \\
 & \text{C}\text{. less than }3\times {{10}^{-5}}m \\
 & \text{D}\text{. more than }3\times {{10}^{-5}}m \\
\end{align}\]

Answer 1

Hint: Ozone layers is a layer which is found in earth’s stratosphere, its role is to absorb the harmful ultraviolet radiation from the sun. It absorbs up to 99% of the sun’s medium frequency UV radiation. The ultraviolet region lies between X-rays and the visible region of the electromagnetic spectrum.

Complete answer:
The ozone layer is a layer of \[{{\text{O}}_{3}}\] which shields us from the harmful radiation if ozone layer wasn’t there then the radiation from the sun would have damage and affects the life which are exposed to it.
The ultraviolet region has a wavelength range of 100-400nm and the ozone layer absorbs the radiation medium frequency of UV or medium wavelength i.e. nearly from 200nm to 300nm.
As\[1nm={{10}^{-9}}m\], we can say that the ozone layer absorbs radiation of wavelength less than\[\text{less than }3\times {{10}^{-7}}m\], converting 300nm in metres.

Hence, the correct option is A.

Additional information:
The Ozone layer was discovered by Charles Fabry and Henri Buisson in 1913. They studied the radiation coming from the sun’s surface and the radiation which was being received by the earth’s ground and that is when they figured out that there was no radiation below 312nm. From this they concluded that there was some layer which was absorbing the radiation coming from the sun.

Note: Conversion of unit should be done properly, here the options are given in metres and the wavelength are usually given in nanometre and there are two options which have different powers one can mistakenly take C as the correct option if they don’t know conversion. Precisely, an ozone layer absorbs radiation from 200nm to 315nm.