Torque experienced by compass needle

In summary, the torque experienced by the compass needle is due to the magnetic moment of the compass/magnet and the Earth's magnetic field. The magnetic moment is aligned with the axis pointing from South to North, while the direction and strength of the magnetic field vary depending on the location of the compass on the Earth's surface. This results in an angle between the magnetic moment and the magnetic field, causing the needle to experience a torque until it reaches equilibrium. The angle of dip also contributes to this torque, but it is not clear which component of the Earth's magnetic field is responsible for it. Images of the Earth's magnetic field would help in understanding this concept better.
  • #1
Qaztgbe
10
0
The torque experienced by the compass needle is m X B , m being the magnetic moment of the compass/magnet and B being the Earth's magnetic field. The magnetic moment is along the axis pointing from South to North and the magnetic field will depend on where the compass is on the surface of the earth.

I can't understand how it's experiencing a torque. Doesn't the needle always point in the direction of the field? Won't the axis be in the direction of the field itself? How is the angle between them anything other than 0°?
How does the angle of dip contribute to this torque? Infact, I can't even understand which component of the Earth's magnetic field is causing this.
Any links to images of the field etc. would really help.
 
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  • #2
the Earth's B field will torque it until it reaches equilibrium.
 

1. What is torque experienced by a compass needle?

Torque experienced by a compass needle is the rotational force acting on the needle due to the Earth's magnetic field. It causes the needle to align itself with the Earth's magnetic field.

2. How is torque experienced by a compass needle measured?

The torque experienced by a compass needle is measured in units of Newton-meters (N*m). This can be calculated by multiplying the force acting on the needle (in Newtons) by the distance from the center of rotation to the point where the force is applied (in meters).

3. What factors affect the torque experienced by a compass needle?

The torque experienced by a compass needle is affected by the strength and direction of the magnetic field, the mass and shape of the needle, and any external forces acting on the needle.

4. How does the direction of the magnetic field affect the torque experienced by a compass needle?

The direction of the magnetic field determines the direction in which the compass needle will point. The greater the angle between the magnetic field and the needle, the greater the torque experienced by the needle.

5. Can the torque experienced by a compass needle be altered?

Yes, the torque experienced by a compass needle can be altered by changing the magnetic field or by applying external forces on the needle. This can cause the needle to point in a different direction or even cause it to stop aligning with the magnetic field altogether.

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