Q1.
But why does Earth behave like a magnet?
Answer
Because of moving electric currents deep inside the Earth. In the core, liquid iron is constantly in motion, and this movement creates electric currents. Those currents, exactly like the current in your coil, generate a magnetic field — and that field spreads far out beyond the surface of the planet.
Why this ties the chapter together: it is the same principle you tested in Activity 4.1. A current produces a magnetic field. The Earth is simply an enormous version of the same thing — which is why a freely suspended magnet, or a compass needle, rests along the north–south direction.
Two consequences of the Earth's magnetic field:
- Many migratory birds, fish and animals use it to navigate across continents and oceans.
- It acts as a shield, blocking harmful particles coming from space, and so helps protect life on Earth.