# Force acting on a current carrying conductor within a magnetic field

• sss
In summary, the figure shows a coil wrapped around the central arm of a thin metallic plate, with current flowing through the coil and magnetizing the arm. The direction of the current and magnetic flux are perpendicular to each other, so a force is exerted on the arm. If the magnetic field is not external to the arm, the bi-directional force (reaction force) of the opposite direction would also be present.
sss
I am new to this forum, and this is my first post. Please bear with me if my query has any inaccuracies.

In the attached figure, a coil is wrapped around the central arm of a flat H-shaped thin metallic plate (such as iron). DC current flows through the coil and magnetizes the arm. At the same time, DC current also flows from another source through the plate as shown in the figure. Within the central arm, the directions of flow of the magnetic flux and current are perpendicular to each other.

If B is the magnetic flux density, L is the length along which the current I flows through the arm, does the plate experience a force F according to the equation F = B I L ?

I am asking this question because generally when we read about force acting on a current carrying conductor in a magnetic field, the magnetic field is understood to be external to the conductor. In this case, it is not. Hence, the query.

Last edited by a moderator:
berkeman
Yes i think there would be a BiL force and it will be perpendicular to the plane of the page.

But i don't understand why you think that the magnetic field is not external in this case. Because it runs through the interior of the H-shaped conductor? But this happens for all external magnetic fields, they can penetrate through any conductor.
BiL force will not happen if the external magnetic field doesn't penetrate inside the conductor where the charge carriers flow and makeup the current i.

anuttarasammyak
Delta2 said:
Yes i think there would be a BiL force and it will be perpendicular to the plane of the page.
I would add that the coil gets reaction force of the opposite direction. The conductor sheet and wrapping coil repulse and no perpendicular motion would take place in total apparatus, if no rupture occurs.

Delta2

## 1. What is the force acting on a current carrying conductor within a magnetic field?

The force acting on a current carrying conductor within a magnetic field is known as the Lorentz force. It is a vector quantity that is perpendicular to both the direction of the current and the direction of the magnetic field.

## 2. How is the direction of the force determined?

The direction of the force is determined by the right-hand rule. If the thumb of the right hand points in the direction of the current and the fingers point in the direction of the magnetic field, then the palm will face in the direction of the force.

## 3. What factors affect the magnitude of the force?

The magnitude of the force depends on the strength of the magnetic field, the current flowing through the conductor, and the length of the conductor within the magnetic field.

## 4. How does the angle between the current and the magnetic field affect the force?

The force is greatest when the current and the magnetic field are perpendicular to each other. As the angle between them decreases, the force also decreases.

## 5. What is the practical application of this force?

This force is used in various technologies such as electric motors, generators, and particle accelerators. It is also the basis for the operation of devices like loudspeakers, headphones, and magnetic levitation trains.

• Electromagnetism
Replies
7
Views
1K
• Electromagnetism
Replies
10
Views
202
• Electromagnetism
Replies
27
Views
1K
• Electromagnetism
Replies
15
Views
1K
• Electromagnetism
Replies
8
Views
823
• Electromagnetism
Replies
6
Views
1K
• Electromagnetism
Replies
61
Views
2K
• Electromagnetism
Replies
21
Views
1K
• Electromagnetism
Replies
5
Views
902
• Electromagnetism
Replies
10
Views
3K