Does a current carrying wire attached to a magnet generate a force?

AI Thread Summary
A current-carrying wire in a magnetic field generates a force, which, according to Newton's third law, also exerts an opposing force on the stator magnets creating the magnetic field. If magnets are attached directly to the rotor with stationary current-carrying wires, the system may still function as a motor, but the interaction between the forces needs careful consideration. The proposed setup involves loops of wire with current flowing in one direction and magnets with the same poles facing inward. The effectiveness of this configuration in producing rotation depends on whether the forces cancel each other out or not. Understanding these interactions is crucial for determining the motor's functionality.
sven1019
Messages
2
Reaction score
0
I have a bit of a theoretical question. If one has a current carrying wire in a magnetic field such as in an electric motor rotor, does the resulting force on the wire also impart an opposing force on the stator magnets which are producing the magnetic field as Newton’s third law says? Also, if one were to instead attach the magnets directly to the outside of the rotor instead of to the stator so that the current carrying wires are stationary relative to the magnets, would the resulting system still function and rotate the rotor as a normal motor or would any opposing forces in this system cancel each other out resulting in no rotation?

Thank you.
 
Physics news on Phys.org
does the resulting force on the wire also impart an opposing force on the stator magnets which are producing the magnetic field as Newton’s third law says?
Sure. The wire has its own magnetic field, too, giving a force on the source of the magnetic field.

Can you draw a sketch of your proposed setup?
 
I apologize, I can't attach a drawing. Imagine a large amount of rectangular, current carrying loops wrapped around an axle much like a slinky wrapped around a rod with magnets fixed to the outside of the loops. The current carrying loops would all have current flowing in the same direction and all magnets having the same poles facing inward (lets say north facing inward). Would this still function as a motor, or would the force of the current carrying wire be canceled out by a force on the magnets in the opposite direction?
 
Susskind (in The Theoretical Minimum, volume 1, pages 203-205) writes the Lagrangian for the magnetic field as ##L=\frac m 2(\dot x^2+\dot y^2 + \dot z^2)+ \frac e c (\dot x A_x +\dot y A_y +\dot z A_z)## and then calculates ##\dot p_x =ma_x + \frac e c \frac d {dt} A_x=ma_x + \frac e c(\frac {\partial A_x} {\partial x}\dot x + \frac {\partial A_x} {\partial y}\dot y + \frac {\partial A_x} {\partial z}\dot z)##. I have problems with the last step. I might have written ##\frac {dA_x} {dt}...
Thread 'Griffith, Electrodynamics, 4th Edition, Example 4.8. (Second part)'
I am reading the Griffith, Electrodynamics book, 4th edition, Example 4.8. I want to understand some issues more correctly. It's a little bit difficult to understand now. > Example 4.8. Suppose the entire region below the plane ##z=0## in Fig. 4.28 is filled with uniform linear dielectric material of susceptibility ##\chi_e##. Calculate the force on a point charge ##q## situated a distance ##d## above the origin. In the page 196, in the first paragraph, the author argues as follows ...
Back
Top