Phys 202 1st Edition Lecture 15Outline of Last Lecture I. How to solve magnetic field problemsOutline of Current Lecture II. Biot-Savart LawIII. Ampere’s LawIV. Solenoid Current LectureBiot-Savart Law:Current gives rise to the B field. The Biot-Savart Law relates a magnetic field to the current that it comes from in a similar way thatCoulomb's law relates an electric fields to the point charge that it comes from. Consider an electric wire with a length L carrying a current I. A magnetic field of magnitude B emanates from this wire out to a distance r from the wire. The equation for the magnitude of the magnetic field around this wire is;ΔB=(µo/4πr)i(ΔLrsin(θ)/r3) = (µ0/4π)(iΔl/r2)sin(θ)µo in this equation is a fundamental magnetic constant which is equal to 4πx10-7 Br I θAmpere’s law:Ampere’s law states that the integral of B around any closed mathematical path equals µ0 times the current intercepted by the area spanning the path. In other words, if you add up the magnetic field at each point along a certain path encircling your current-carrying wire, then it will equal the amount of current enclosed by this path. Ampere’s law is represented by the equation:These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.∫B ∙ ∆ L=μ0ISolenoid:A solenoid is a long, thin loop of wire, wrapped around cylinder in order to produce a uniform magnetic field when an electric current is passed through it. A solenoid is a type of electromagnet when the purpose is to generate a controlled magnetic field. If we want to find the magnitude of the magnetic field B around a loop of a solenoid in free space, we would use the equation;B=µ0(NI/L)Where µ0 is the magnetic constant, I is the current, N is the number of turns, and L is the length of the loop. For a solenoid immersed in some other material, we would multiply this equation by the relative permeability of the material
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