Electrically charged particles from space traveling at speeds of several hundred km/sec can…

Answer: (a) The Earth’s magnetic field diverts them towards its poles.

The Earth's magnetic field stops these particles. It shields life from harmful particles from space, and charged particles such as the solar wind are steered towards the magnetic poles. Neither the ozone layer nor atmospheric moisture does this.

• ✓ (a) The magnetic field shields the Earth, blocking harmful particles from space. When the solar wind (charged particles from the Sun) reaches the Earth's atmosphere, it is directed towards the magnetic poles. There it meets atmospheric gases and produces auroras instead of reaching the surface.
• ✗ (b) The ozone layer shields the surface from the Sun's ultraviolet radiation. It does not reflect charged particles back into space.
• ✗ (c) Most of the atmosphere's water vapour and clouds lie in the troposphere, the lowest layer. Moisture plays no part in stopping fast-moving charged particles from space.
• ✗ (d) Statement (a) is correct, so 'none of the above' cannot be the answer.

Remember · The Earth's magnetic field, generated in the liquid iron outer core, steers charged particles like the solar wind towards the poles, where they cause auroras. Ozone, by contrast, screens out UV radiation.

📘 Read it in NCERT: Class 8 Curiosity, Ch 4 (practise this chapter) · Class 9 Understanding Society: India and Beyond, Ch 3 (practise this chapter) · Class 10 Science, Ch 13 (practise this chapter)

Question: UPSC Civil Services (Preliminary) 2012, General Studies paper. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). · Report an error