Unformatted text preview: ~ A inside and outside of an inFnite solenoid of radius R with n turns per centimeter, each carrying current I . ±ind the solenoid which is symmetric about the axis of the solenoid. HINT : You can come up with a very simple way to compute ~ A by putting together • The magnetic ²ux, Φ B = R ~ B · d~a • The deFnition ~ B = ~ ∇ × ~ A • Stoke’s theorem. 8. Purcell 7.14: Crossbar sliding in magnetic Feld (20 pts). I don’t like Purcell’s subparts, so please do the following: (a) Write down a di³erential equation of the form dv/dt = something that governs the motion of the sliding crossbar. (b) Integrate this to Fnd the velocity v ( t ) for all t > 0. (c) Compute the total distance that the cross bar moves. (d) Show that the total energy dissipated in the resistor makes sense given the initial velocity of the crossbar....
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- Spring '08
- Mass, Magnetic Field, pts, Purcell