1. ### How to determine the number of turns of the winding?

1) B = Φ/S = (4.2*10^(-3) Wb)/(2.5*10^(-3) m^2) = 1.68 T 2) Using electrical steel magnetization curve given in the textbook: magnetic field strength H corresponding to magnetic flux density 1.68 T is equal to 6000 A/m. 3) L is a length of the middle magnetic line of the core (Fig. 2). L =...
2. ### I Faraday's law or Lorenzt force?

A student in my physics class posted, in a group, a wrong answer to a question. The situation was: A plane has a wire extended between the tips of its wings and flies through a magnetic field, perpendicularly, while accelerating. The question was: What will be the induced current? His answer...
3. ### I What exactly is Reluctance?

Electrical resistance is due to electrons colliding with the atoms of the conductor. In a magnetic circuit reluctance is analogous to resistance in an electric circuit. Just as resistance impedes the flow of electrons in an electric circuit, reluctance impedes the flux in a magnetic circuit but...
4. ### Engineering Deriving the circuit approximation of a magnetic circuit

Homework Statement For the magnetic circuit: Derive the circuit approximation. Compute all magnetic fluxes if the total solenoid current is I. Homework Equations Rm = L / μS The Attempt at a Solution [/B] Mostly, right now, I'm just trying to determine the magnetic circuit equivalent...
5. ### Question about transformer reflected source

The following show the idea how a Thevenin equivalent source is used to replace the primary circuit of transformer. https://www.dropbox.com/s/0kaazx1d1srgirz/reflectedsource.jpg?dl=0 https://www.dropbox.com/s/0kaazx1d1srgirz/reflectedsource.jpg?dl=0 In textbook it is commonly stated that the...
6. ### Mmf in transformer

I am studying about transformer and get confused about some concept. I have learn that in an ideal simple transformer the primary has two components of current: Magnetization current i.e. the open-secondary primary current. Current that (ignoring small leakage inductances) finds it way (via...
7. ### Ampere's law and magnetic circuit

For magnetic circuit there is an equation NI=HL. This equation is obtained by applying Ampere's law. H is magnetic field intensity and L is the length of the circuit. In following picture the equation reduced to I=HL as there is only one turn...
8. ### Permeability in ferromagnetic material (AC)

Homework Statement The following coil-wound core (core length = L , Gap length = lg, cross- sectional area = A , core permeability = only hysteresis graph is given, N = N turns) is driven by a Voltage source, is known that the current in the coil is 60hz AC. Determine...
9. ### Slab Beam of electrons through Neutralising Ions

Homework Statement A slab beam of electrons of thickness a, width w >> a, charge density (-ρb ), (Take ρb to be positive.) and velocity vbez passes through a channel of neutralizing ions with charge density f*ρb where f is some number between zero and one (all parameters given above apply in...
10. ### Response time of a magnetic circuit and its elements

This one is for people working with electromagnets (more specific, DC) etc. I have a few questions that I am struggling with: I am quite comfortable with the concept of the response time (time constant) of a coil in free space, μ0 =4π x 10-7 . The thing I am struggling with is the response time...