Rankers Physics

Magnetic Properties of Matter: Practice Problem & Solution

12. A compass needle which is allowed to move in a horizontal plane is taken to a geomagnetic pole. It: (2012 Pre)
Will become rigid showing no movement
Will stay in any position
Will stay in north-south direction only
Will stay in east-west direction only

Solution Explained:

To solve this problem, we apply the core principles of Magnetic Properties of Matter. Understanding the underlying formula is key to arriving at the correct answer below:

At the geomagnetic poles, the Earth's magnetic field is entirely vertical, meaning the horizontal component $B_H$ is zero. A compass free to rotate only horizontally experiences no directing torque and will stay in any position.

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