This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: song (shs546) – Practice HW 15 Solutions – weathers – (22202) 1 This print-out should have 9 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001 0.0 points A cubic magnet is levitating above a super- conducting surface. μ ? ? i N S Determine both the direction of the in- duced magnetic moment vectorμ , and the direction of the induced current (as viewed from above). Let CW stand for “clockwise”, and CCW for “counterclockwise”. 1. vectorμ is down, current is 0 2. vectorμ = 0, current is CW 3. vectorμ is up, current is CCW 4. vectorμ = 0, current is CCW 5. vectorμ is down, current is CW correct 6. vectorμ is up, current is CW 7. vectorμ is down, current is CCW 8. vectorμ is up, current is 0 Explanation: Magnetic induction induces eddy-currents in a superconducting medium. In order to levitate the magnet, there must be a magnetic field created by the induced current. If we adopt the view of a current loop as a little bar magnet (magnetic moment vectorμ ), its south pole must point up to repel the levitating magnet. Therefore, since vectorμ in the same direction as the north pole of its “repre- sentative bar magnet,”, vectorμ points down. To an observer above the setup, the induced current must run clockwise to create a magnetic field pointing downward....
View Full Document
- Spring '00
- Magnetism, Magnetic Field, Correct Answer