2012 · GeographyPrevious Year Question
Q20.
Electrically charged particles from space travelling at speeds of several hundred km/sec can severely harm living beings if they reach the surface of the Earth. What prevents them from reaching the surface of the Earth?
A. The Earth's magnetic field diverts them towards its poles.
B. Ozone layer around the Earth reflects them back to outer space.
C. Moisture in the upper layers from reaching the surface of the Earth.
D. None of the statements (a), (b) and (c) given above is correct.
Answer

A

Explanation

Most of the solar wind is diverted to poles due to Earth's magnetic field lines. Although a big solar flare can interfere with communication systems and power supplies doing a blackout at some places on the globe, the possibilities are there but marginal. The Earth's magnetosphere (magnetic field) acts as a shield diverting charged particles (solar wind) towards the poles, which is why auroras (Northern and Southern Lights) appear near polar regions.