Finding force between solenoid and magnet

Thread starter Mitchell Richardson
Start date Mar 21, 2024
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Force Magnet Solenoid

In summary, the interaction between a solenoid and a magnet involves the generation of a magnetic field by the solenoid when an electric current flows through it. The strength and direction of this field can influence the force exerted on a nearby magnet, leading to attraction or repulsion depending on the alignment of their magnetic poles. The force can be calculated using principles of electromagnetism, taking into account factors such as the solenoid's current, the number of turns, and the distance from the magnet. The phenomenon is utilized in various applications, including electric motors and magnetic levitation systems.

Mar 21, 2024

Mitchell Richardson

Homework Statement: I just have a question about finding the force between a solenoid and a magnet at different distances. I have tried using a combination of B=μnI and F=BIL, however the answers I am getting are extremely off from the values that I have measured. Is this equation wrong and if so is there one that achieves what I want?

Relevant Equations: $$B=\mu nI $$
$$F=\frac{BIL}{2 \pi r}$$
$$F=\frac{μn I^{2} L}{ 2 \pi r}$$

$$\mu = 4\pi \times 10^{-7}$$
$$n = \frac{180}{0.135} = 1333.33$$
$$I = 1.85$$
$$L = 22.619$$
$$r = 0.014$$

$$F= \frac{\mu \times 1333.33 \times 1.85^{2} \times 22.619}{2 \pi \times 0.014}$$

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Mar 21, 2024

haruspex

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Please describe the set up in detail and provide units with the numbers.

Mar 21, 2024

nasu

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Where did you get the second equation? What force is described by it?

FAQ: Finding force between solenoid and magnet

What is the basic principle behind the force between a solenoid and a magnet?

The force between a solenoid and a magnet is primarily due to the interaction of magnetic fields. When current flows through the solenoid, it generates a magnetic field, which interacts with the magnetic field of the magnet, resulting in an attractive or repulsive force depending on the orientation of the fields.

How can I calculate the force between a solenoid and a magnet?

The force between a solenoid and a magnet can be calculated using the Lorentz force law and principles of electromagnetism. The force depends on the magnetic flux density, the current in the solenoid, and the distance between the solenoid and the magnet. For a more precise calculation, you may need to use numerical methods or finite element analysis to account for the complex geometry and field interactions.

What factors affect the magnitude of the force between a solenoid and a magnet?

The magnitude of the force is influenced by several factors including the current flowing through the solenoid, the number of turns in the solenoid, the permeability of the core material, the strength of the magnet, and the distance between the solenoid and the magnet. Increasing the current or the number of turns in the solenoid generally increases the force.

Can the direction of the force between a solenoid and a magnet be controlled?

Yes, the direction of the force can be controlled by changing the direction of the current flowing through the solenoid. Reversing the current will reverse the polarity of the solenoid's magnetic field, thereby changing the direction of the force between the solenoid and the magnet from attractive to repulsive or vice versa.

What are some practical applications of the force between a solenoid and a magnet?

This principle is used in various applications such as electromagnetic actuators, relays, magnetic levitation systems, and electric motors. In these devices, controlling the force between a solenoid and a magnet allows for precise movement, switching, or stabilization of components.