1. Magnetism Challenge

2. If an iron bar is placed in a magnetic field, which one of the figures represents the distortion of the field?
Ans. a

3. What is the strength of the B-field at point P?
Ans x 10-5 T

4. What is the direction of the B-field at point P?
Ans. Out of screen

5. Electrons flow along a wire directed out of the page
Electrons flow along a wire directed out of the page. What is the direction of the magnetic force on the wire?
Ans. down

6. What is the magnitude of the B-field at point P, if the current is 1 A?
Ans. 5 x 10-6 T

7. Which diagram shows the correct magnetic field around the wire?
Ans. A (careful it is showing electron flow)

8. Which one is the correct representation?
Ans. A

9. Which one is correct?
Ans. C

10. When the switches are closed will these two bars attract or repel?
Ans. attract

11. Which is correct?
Ans. B and D

12. What is the correct polarity on the paper clips?
Ans. D

13. Where is the North pole?
Ans. C (ignore current arrows – look at +, - to determine current flow)

14. What is the direction of the magnetic field at the center of the loop?
Ans. Into screen

15. Where is the South pole?
Ans. D

16. What happens to the strength of the field if the resistance decreases?
Ans. strengthens

17. What is the resistance? Where is the North pole?
Ans. 8 ; D

18. What is the direction of the magnetic force on the segment AB?
Ans. Out of screen

19. What is the direction of electron flow in the wire?
Ans. Down wire from B to A

20. What is the direction of the current in the coil?
Ans. Down in front

21. Where is the field strongest?
Ans. C

22. What is the pole at K?
Ans. N

23. What is the force on segment bc? (magnitude and direction)
Ans Newtons (assume 1 A current); directed into screen

24. If this wire were made from a loose chain, would it expand to form a circle, compact to a point, or nothing?
Ans. compact

25. Which shows the correct electric field around a negative charge?
Ans. D

26. Which is correct?
Ans. C

27. Which shows the correct magnetic field around a positive current moving into the board?
Ans. A