What is Ampere's law: Definition and 214 Discussions

In classical electromagnetism, Ampère's circuital law (not to be confused with Ampère's force law that André-Marie Ampère discovered in 1823) relates the integrated magnetic field around a closed loop to the electric current passing through the loop. James Clerk Maxwell (not Ampère) derived it using hydrodynamics in his 1861 published paper "On Physical Lines of Force" In 1865 he generalized the equation to apply to time-varying currents by adding the displacement current term, resulting in the modern form of the law, sometimes called the Ampère–Maxwell law, which is one of Maxwell's equations which form the basis of classical electromagnetism.

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    Ampere's Law and current density

    The current density inside a long, solid, cylindrical wire of radius a = 10 cm is in the direction of the axis and varies linearly with the radial distance r cm from the axis according to J = J0 r / a with J0 =0.5 A/cm2 . Find the magnetic field in μT at r = 0.045 m Ok I know from amperes law...
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    Help with ampere's law problem

    urgent help with ampere's law problem The problem reads as: Consider a hollow wire of inner radius a and outer radius b carrying a current I. Use Ampere's law to find the magnitude of the magnetic field B(r) as a function of distance r from the center of the wire. A) What is the current...
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    How is the Displacement Current Used to Resolve Issues with Ampere's Law?

    Hi I was wondering if you can help me. How is the concept of the displacement current used to resolve the ploblems with the application of Ampere's law. I know that the modified ampere's law is curl(B)=Mew(0)(jc+jd) I just know how the displacement current jd is used to solve the...
  4. M

    Urgent: Help Needed on Ampere's Law Probolem (Totally Lost)

    The question is: Between two long parallel cylinders of radius "a" and "b" (non-coaxial) and an axal separation of "c", a steady current of "I" flows. (See attachment below) Show that the inner cylinder (radius "a") has a constant magnetic field. Use Ampere's Law. [Hint: 0 = 1 + (-1)]...
  5. M

    Ampere's Law: Solving Parallel Cylinder Problem

    The question is: Between two long parallel cylinders of radius "a" and "b" (non-coaxial) and an axal separation of "c", a steady current of "I" flows. (See attachment below) Show that the inner cylinder (radius "a") has a constant magnetic field. Use Ampere's Law. Indicate all steps clearly...
  6. M

    Ampere's Law: Constant Magnetic Field b/w Non-Coaxial Cylinders

    The question is: Between two long parallel cylinders of radius "a" and "b" (non-coaxial) and an axal separation of "c", a steady current of "I" flows. (See attachment below) Show that the inner cylinder (radius "a") has a constant magnetic field. Use Ampere's Law. Indicate all steps clearly...
  7. L

    Simple Theoretical Question about Ampere's Law

    Hi all, This one's an easy one: What's the easiest way of telling whether a current is "enclosed" in a closed path or not? And how can I tell when a current effectively cancels itself out? For example, let's say I have a spherical shell with surface current density K [A/m], and I want to...
  8. R

    How Does Ampere's Law Apply to a Solid Wire with Non-Uniform Current Density?

    Magnetic field due to a solid wire of current using Ampere's circuital law. Current flows with density J=J_{o}\frac{U}{r}a_{z} [A/m^2] along long solid cylindrical wire of radius a having the z-axis as its axis. Find H \oint_{c}H\cdot\,dl=\int_{s}J\cdot\,dS Am I on the right way to...
  9. C

    Solve Ampere's Law: Get Help w/ Figure P30.23

    Need Help -- Ampere's Law http://www.webassign.net/pse/p30-21alt.gif Figure P30.23 is a cross-sectional view of a coaxial cable. The center conductor is surrounded by a rubber layer, which is surrounded by an outer conductor, which is surrounded by another rubber layer. In a particular...
  10. A

    Question about displacement current and ampere's law

    A 0.230-A current is charging a capacitor that has circular plates 10.0 cm in radius. (a) If the plate separation is 4.00 mm, what is the time rate of increase of electric field between the plates? (b) What is the magnitude of the magnetic field between the plates 5.00 cm from the...
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    Calculating Magnetic Field Inside a Toroidal Sample Using Ampere's Law

    Can someone help me with this please? Consider a toroidal sample of magnetic material wound, uniformly, with coils of wire that carry a current I. If the total number of coils is N and the relative permeability of the material is μr, calculate the magnetic field B, inside the toroid at radius...
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    Fallacy of Ampere's Law: Understanding Magnetic Fields Near Conducting Wires

    If we want to find out the net magnetic field on a point near a conducting wire , we use ampere's law by take a closed surface in form of A CIRCLE...with radius equal to the distance of the point fromt he where...but where ampere fails is that it gives the same result for both a finite...
  13. C

    Researching Ampere's Law: Need Help Finding Resources

    Hi all, I stumbled upon this page from google. I have to write a research paper for ampere's law. However, I cannot get enough info to meet the minimum number of pages for the paper. I did a google search at which I only got a paragraph on ampere's law...
  14. N

    Apply the ampere's law to the infinite solenoid

    how to apply the ampere's law to the infinite solenoid... how we find the equation for the magnetic field ?? who can help...
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