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๐ฌ Think about it
Why does a compass needle always point north? Because the whole Earth acts like a giant magnet. That magnet does more than guide travellers — it shields us from space. Let us find out how.
Why does Earth behave like a giant magnet?
- A freely suspended magnet settles in a fixed direction.
- This is because Earth itself behaves like a giant magnet.
- The movement of molten iron in Earth's core may cause this.
- So the region around Earth has a magnetic field.
Example:
A compass needle points north because Earth's magnetism pulls it, like a hidden giant magnet inside the planet.
How does the magnetic field protect life?
- Earth is hit by tiny high-energy particles from space.
- Cosmic rays come from across the universe; solar wind comes from the Sun.
- These can damage the atmosphere and reduce the ozone layer.
- But the magnetic field pushes many of them away, keeping life safe.
The Magnetic Shield
Harmful particles from space and Sun
↓
Magnetic field acts
Earth's field works like a shield.
↓
Particles pushed away
Most harmful particles are deflected.
↓
Atmosphere and life stay safe
Important Points
- Earth behaves like a giant magnet with a magnetic field.
- Cosmic rays and solar wind are harmful space particles.
- The magnetic field deflects them and protects life.
โ Test Yourself
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Why does a compass needle point in a fixed direction?
View Answer
Because Earth behaves like a giant magnet. -
What may cause Earth's magnetic field?
View Answer
The movement of molten iron in Earth's core. -
What are cosmic rays?
View Answer
High-energy particles that come from far across the universe. -
What is the solar wind?
View Answer
High-energy particles that come from the Sun. -
How does the magnetic field help?
View Answer
It pushes harmful particles away, keeping the atmosphere and life safe.
Important Definitions
- Magnetic field — the region around a magnet where its effect is felt; Earth has one too.
- Cosmic rays — high-energy particles that come from far across the universe.
- Solar wind — high-energy particles that come from the Sun.
๐ NCERT Question 8 — Imagine Earth's magnetic field
Imagine Earth's magnetic field suddenly disappeared. What problems could arise for life? Explain.
View Answer →
