Oscillation of a bar magnet

In summary, if a magnet is displaced from its equilibrium position by a small angle (theta), it will oscillate with a period T= 2*pi*sqrt((M(L^2 + a^2)/12)/(mB)), where M is the mass, L is the length, a is the width, and B is the Earth's horizontal component of magnetic field. The method to derive this equation involves using torque (tau = I*@) and considering the magnet's oscillations as similar to a physical pendulum.
  • #1
Marcstylzzz
1
0
Please help, if a magnet is displaced from its equilibrium position by a small angle (theta), show that it will oscillate with a period T given by T= 2*pi*sqrt(I/mB)
I = moment of inertia of the bar magnet and equals M(L^2 + a^2)/12
B = Earth's horizontal component of magnetic field
M is the mass
L is the length and a its width
 
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  • #2
Is the magnet you're referring to oscillating like a compass needle does (the period they gave looks a lot like the period for the physical pendulum)?

If that is the case, then suitable method would be to find a way to write out an equation displaying SHM (much like the pendulum with oscillations of small angles). A good way of deriving it would probably be using torque (tau) as tau = I*@, in which I is moment of inertia and @ is angular acceleration.
 
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  • #3


The oscillation of a bar magnet is a result of the interaction between the Earth's magnetic field and the magnet's own magnetic field. When the magnet is displaced from its equilibrium position by a small angle, it experiences a restoring torque that brings it back to its original position. This back-and-forth motion creates an oscillation.

To understand the period of this oscillation, we can use the equation T= 2*pi*sqrt(I/mB), where I is the moment of inertia of the bar magnet, m is the mass of the magnet, and B is the Earth's horizontal component of the magnetic field.

The moment of inertia of the magnet, represented by I, can be calculated using the formula I = M(L^2 + a^2)/12, where M is the mass of the magnet, L is the length, and a is the width of the magnet.

Substituting this value of I into the equation for the period, we get T= 2*pi*sqrt((M(L^2 + a^2)/12)/mB).

Simplifying this further, we get T= 2*pi*sqrt((ML^2 + Ma^2)/(12mB)).

Since the mass of the magnet, represented by M, is common in both the numerator and denominator, we can cancel it out, leaving us with T= 2*pi*sqrt((L^2 + a^2)/(12B)).

This equation shows that the period of oscillation of a bar magnet is dependent on the length and width of the magnet, as well as the Earth's magnetic field. As the length or width of the magnet increases, the period of oscillation will also increase. Similarly, a stronger Earth's magnetic field will result in a shorter period of oscillation.

In conclusion, the oscillation of a bar magnet is a result of the interplay between its own magnetic field and the Earth's magnetic field. The period of this oscillation can be calculated using the equation T= 2*pi*sqrt(I/mB), where I is the moment of inertia of the magnet, m is its mass, and B is the Earth's magnetic field.
 

Related to Oscillation of a bar magnet

1. What is oscillation of a bar magnet?

Oscillation of a bar magnet is the back and forth movement of a magnet around its equilibrium position, caused by the interaction between its magnetic field and an external force.

2. How does a bar magnet oscillate?

A bar magnet oscillates due to a phenomenon called magnetic dipole moment, which is the measure of the strength and direction of a magnet's magnetic field. When a bar magnet is placed in an external magnetic field, the forces of attraction or repulsion cause it to oscillate.

3. What factors affect the oscillation of a bar magnet?

The oscillation of a bar magnet can be affected by factors such as the strength of the external magnetic field, the distance between the magnet and the source of the field, and the mass and shape of the magnet.

4. How can the oscillation of a bar magnet be measured?

The oscillation of a bar magnet can be measured using a magnetometer, which is a device that can detect and measure changes in a magnetic field. The period, or time it takes for the magnet to complete one full oscillation, can also be measured using a timer or stopwatch.

5. What are the applications of oscillation of a bar magnet?

The oscillation of a bar magnet has various applications in fields such as engineering, physics, and geophysics. It is used in devices such as compasses, electric motors, generators, and magnetic resonance imaging (MRI) machines. It also plays a crucial role in understanding the Earth's magnetic field and its changes over time.

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