Point of application of magnetic torque.

In summary, the conversation discusses the application of a torque equation in determining the effect of a uniform magnetic field on a current-carrying loop. It is noted that the torque is independent of the axis chosen and is equivalent to a couple in mechanics. This concept is illustrated through the example of a sphere with a current-carrying ring in rotational equilibrium on an inclined plane.
  • #1
anmol21
3
0

Homework Statement



Hello,
When a current carrying loop (of any shape) is placed in a uniform magnetic field B , the field is given by MχB where M is the magnetic moment vector I*A where I Is current and A is the area vector. I want to know at which point or for which axis is the torque applied given by the above equation.

Homework Equations



ζ=MχB
M=I*A

The Attempt at a Solution

 
Physics news on Phys.org
  • #2
welcome to pf!

hi anmol21! welcome to pf! :smile:

if B is uniform, the resultant force will be zero, so the effect is a pure torque

so the circuit will turn about the centre of mass of whatever the circuit is fixed to (or about whatever axis that is constrained to turn around)
 
  • #3
Thanks tiny-tim :)

So is the magnetic torque independent of the axis chosen ?

For example , Consider a sphere with a ring attached to it , with current I in the ring , in rotational equilibrium on a rough inclined plane. The magnetic field is vertically downwards and gravity is present. So we can equate the torque due to gravity and the magnetic torque at any point . So will be the magnetic torque be same even at the point of contact of the sphere with the ground or the centre of the sphere ?
 
  • #4
hi anmol21! :smile:

the magnetic torque of a uniform magnetic field on a circuit is a couple

it is exactly the same as a couple (or "pure moment") in mechanics: it has the same moment about any point

"a system of forces with a resultant (a.k.a. net, or sum) moment but no resultant force"

"… the moment (torque) of a couple is independent of the reference point P: Any point will give the same moment. In other words, a torque vector, unlike any other moment vector, is a "free vector"."​

both quotes from http://en.wikipedia.org/wiki/Couple_(mechanics) :wink:
 
  • #5
thanks a lot , that clears it up :)
 

1. What is the point of application of magnetic torque?

The point of application of magnetic torque is the location where the force of a magnetic field acts on an object. It is the point where the object experiences a twisting or turning motion due to the interaction between the magnetic field and its magnetic moment.

2. How is the point of application of magnetic torque determined?

The point of application of magnetic torque can be determined by examining the direction of the magnetic field and the orientation of the object's magnetic moment. The point of application is typically located at the point where the magnetic field and the magnetic moment are perpendicular to each other.

3. Does the point of application of magnetic torque affect the magnitude of the torque?

Yes, the point of application of magnetic torque can affect the magnitude of the torque. The closer the point of application is to the object's center of mass, the smaller the torque will be. This is because the distance between the point of application and the axis of rotation is smaller, resulting in a smaller lever arm.

4. Can the point of application of magnetic torque be changed?

Yes, the point of application of magnetic torque can be changed by changing the orientation of the object's magnetic moment or by changing the strength or direction of the magnetic field. This will result in a different location where the force of the magnetic field acts on the object, thus changing the point of application of the torque.

5. How is the point of application of magnetic torque used in practical applications?

The point of application of magnetic torque is used in various applications such as electric motors, generators, and magnetic levitation systems. It is also used in scientific research to study the behavior of magnetic fields and their effects on objects. Understanding the point of application of magnetic torque is crucial in designing and optimizing these systems for efficient operation.

Similar threads

  • Introductory Physics Homework Help
Replies
4
Views
269
  • Introductory Physics Homework Help
Replies
1
Views
267
  • Introductory Physics Homework Help
2
Replies
37
Views
2K
  • Introductory Physics Homework Help
Replies
7
Views
139
  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
8
Views
356
  • Introductory Physics Homework Help
Replies
1
Views
612
  • Introductory Physics Homework Help
Replies
3
Views
136
  • Introductory Physics Homework Help
Replies
16
Views
339
  • Introductory Physics Homework Help
Replies
25
Views
209
Back
Top