How much of the Sun's ultraviolet radiation reaches Earth's surface?

1. some of the ultraviolet radiation

2. most of the ultraviolet radiation

3. almost all of the ultraviolet radiation

4. none of the ultraviolet radiation

5. little of the ultraviolet radiation

Option (5)

Explanation:

The ultraviolet rays are found to be present in solar radiation and are allowed to be incident on the earth. These solar radiations are comprised of nearly 8% of UV rays. These UV rays are of three types, namely UV-A, UV-B and UV-C which are harmful to the living organisms on earth. Of all the three, the UV-B and UV-C are highly dangerous that can cause various skin diseases like cancer.

The presence of the ozone layer in the atmosphere acts like a blanket that does not allow these harmful UV radiations to enter into the atmosphere of the earth. The majority of the UV-A is able to reach the earth's surface, but they are not able to cause much harm. So, out of this 8% of total UV radiations, a little amount of it is successful in reaching the surface of the earth.

Thus, the correct answer is option (5).