Force of a changing magnetic field

AI Thread Summary
A changing magnetic field induces an electric potential around a loop of wire, causing stationary charges within the loop to experience a force. To determine the direction of this force when charges are not in a loop, Faraday's Law can be applied, leading to the relationship between electric field (E) and magnetic field (B). The Lorentz force equation, F = q(E + |v x B|), simplifies to F = qE for stationary charges, indicating that the force is influenced by the electric field. The direction of the force can vary based on the orientation of the magnetic field and the electric field, potentially aligning with the loop's curvature once the charge begins to move. Isolating E from Faraday's Law involves solving the associated partial differential equation.
DCN
Messages
8
Reaction score
0
By Faraday's Law, we know that a changing magnetic field can induce a potential around a loop of wire and it follows that any charges in the loop will experience a force, otherwise they wouldn't move. Therefore a changing magnetic field exerts a force on stationary charges.

How do you tell the direction of this force is the charge is not in a loop of wire?
 
Physics news on Phys.org
You also use Faraday law, ∇x E = -∂B/∂t, and solve this for E, but remember that the magnetic field is gone yet, so you have lorentz force, F = q(E + |v x B|), however if the charge is stationnary, then just be force it start moving F = qE, F⊥B just because E⊥B (because of the curl), by this you can see that the force can be in any direction even in the direction of the loop if you put the magnetic field in the right angle,once it started moving perpenducular forces are further applied, this you can expect it to be in the direction for the loop (curvature)of the wire
 
How would you isolate E from Faraday's law?
 
DCN said:
How would you isolate E from Faraday's law?
It's a partial differential equation,
 
Thread 'Inducing EMF Through a Coil: Understanding Flux'
Thank you for reading my post. I can understand why a change in magnetic flux through a conducting surface would induce an emf, but how does this work when inducing an emf through a coil? How does the flux through the empty space between the wires have an effect on the electrons in the wire itself? In the image below is a coil with a magnetic field going through the space between the wires but not necessarily through the wires themselves. Thank you.
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