IAS General Studies Question – 12

Consider the following statements about the Cosmic rays:

1. They are made up of only positively charged particles

2. The major source of Cosmic Rays in universe is Sun

3. They cause Ozone Depletion

Which among the above statements is/ are correct?

[A]Only 1 & 3 are correct

[B]Only 2 & 3 are correct

[C]Only 3 is correct

[D]None of them is correct

Answer: Only 3 is correct

Explanation: The first statement is incorrect. Almost 90% of cosmic rays are protons, about 9% are helium nuclei (alpha particles) and nearly 1% are electrons. This means that Cosmic Rays are not made up of only positively charged particles. The second statement is also incorrect. Cosmic rays may broadly be divided into two categories: primary and secondary. The cosmic rays that originate from astrophysical sources are primary cosmic rays; these primary cosmic rays interact with interstellar matter creating secondary cosmic rays. Sun is not the major source but exactly is a minor source. The Sun also emits low energy cosmic rays associated with solar flares. The third statement is correct. The chain of reactions in the upper atmosphere due to the cosmic rays causes depletion of the ozone but this depletion is small in comparison to the depletion caused by CFCs.

http://en.wikipedia.org/wiki/Cosmic_rays