Solving Solenoid Field Problem: B=urNI & Force on Iron

  • Thread starter Thread starter I_am_learning
  • Start date Start date
  • Tags Tags
    Field Solenoid
AI Thread Summary
The discussion centers on determining the magnetic field strength at a specific axial distance from a finite length solenoid and the force exerted on a piece of iron placed in that field. While the equation B=urNI applies to infinite solenoids, the field strength for finite solenoids requires more complex calculations. The participants acknowledge the challenge of finding the magnetic field outside a finite solenoid, which is not zero as it is for infinite solenoids. Additionally, the force experienced by iron in a magnetic field of 10 tesla is questioned, highlighting the need for further analysis. Understanding these concepts is essential for applying electromagnetic theory in practical scenarios.
I_am_learning
Messages
681
Reaction score
16
Given a solenoid we can find the field inside and at the ends by B=urNI.
Now, what is the field strength at some x -axial distance away from the solenoid?
What force will this field impart on a piece of iron?
 
Last edited:
Physics news on Phys.org
That equation assumes that the solenoid is infinite, in which case the field outside the solenoid is zero. For a finite length solenoid, it is a more difficult problem but one that has ben studied previously I am sure.
 
Leave the problem for finite length solenoid now, Born2bwire.
Even if we calculate the field Strength B, what force will it impart on a piece of iron?
 
thecritic said:
Given a solenoid we can find the field inside and at the ends by B=urNI.
Now, what is the field strength at some x -axial distance away from the solenoid?
What force will this field impart on a piece of iron?

What is the context of your question?
 
berkeman said:
What is the context of your question?
I am just asking two elementary questions
1. What is the magnetic field strength at any given point on the axial line of a finite length current carrying solenoid.
2. What force will a piece of iron experience if it is placed at the point where magnetic filed strength is say 10 tesla.
 
Thread 'Gauss' law seems to imply instantaneous electric field propagation'
Imagine a charged sphere at the origin connected through an open switch to a vertical grounded wire. We wish to find an expression for the horizontal component of the electric field at a distance ##\mathbf{r}## from the sphere as it discharges. By using the Lorenz gauge condition: $$\nabla \cdot \mathbf{A} + \frac{1}{c^2}\frac{\partial \phi}{\partial t}=0\tag{1}$$ we find the following retarded solutions to the Maxwell equations If we assume that...
Maxwell’s equations imply the following wave equation for the electric field $$\nabla^2\mathbf{E}-\frac{1}{c^2}\frac{\partial^2\mathbf{E}}{\partial t^2} = \frac{1}{\varepsilon_0}\nabla\rho+\mu_0\frac{\partial\mathbf J}{\partial t}.\tag{1}$$ I wonder if eqn.##(1)## can be split into the following transverse part $$\nabla^2\mathbf{E}_T-\frac{1}{c^2}\frac{\partial^2\mathbf{E}_T}{\partial t^2} = \mu_0\frac{\partial\mathbf{J}_T}{\partial t}\tag{2}$$ and longitudinal part...
Thread 'Recovering Hamilton's Equations from Poisson brackets'
The issue : Let me start by copying and pasting the relevant passage from the text, thanks to modern day methods of computing. The trouble is, in equation (4.79), it completely ignores the partial derivative of ##q_i## with respect to time, i.e. it puts ##\partial q_i/\partial t=0##. But ##q_i## is a dynamical variable of ##t##, or ##q_i(t)##. In the derivation of Hamilton's equations from the Hamiltonian, viz. ##H = p_i \dot q_i-L##, nowhere did we assume that ##\partial q_i/\partial...

Similar threads

Back
Top