VirtualDynamics UniversitySolved UniversityPhysics ProblemsPhysics 3: Introduction to Electricity & Magnetism <<< Induced Magnetic Field. Ampere's Law >>>Javier Montenegro Joo jmj@VirtualDynamics.OrgReturn to Electricity and Magnetism Index page Return to VirtualDynamics University home page

<<< Induced Magnetic Field. Ampere's Law >>> 
(1) A long straight wire of radius R transports an electric current. Calculate the radial distance where the induced magnetic field due to this current, reduces to a half of its maximum value. (a) Out of the wire (b) inside the wire. Solution The maximum induced magnetic field due to an electric current in a wire, is at the surface of the wire. This is valid for both magnetic fields, exterior and interior. In this problem the surface of the wire is at r = R. The magnetic field induced by a current in a wire is:

EduVirtualLab about oscillations in a rectangular membrane.

(2)
The propulsion system of an interstellartravel vessel includes a long,
straight, solid, cylinder of radius R. The cylinder leads lengthwise an
electrical current I whose density is J = A r, A = Const. Determine:
(a) the constant A (b) the magnetic field in r ≤ R (c) the magnetic
field in r ≥ R.
Solution.
