Download PHYSICS Chapter 21: Magnetism Please answer questions in

PHYSICS
Chapter 21: Magnetism
Please answer questions in complete sentences, indicating the question asked and justifying the answer
when necessary. Show work on problems, including the equation(s) used. Include significant figures and
units in your boxed answer.
21-1
1. In what direction do magnetic field lines always point?
2. There are two kinds of magnetic poles, just like there are two kinds of electric charge. However,
there is one big difference between magnetic poles compared to electric charges. What is the
difference?
3. What kind of magnetic pole is the North Geographic Pole?
4. The earth has a fairly strong magnetic field, but Mars does not. What is the principal reason for
this difference?
5. Draw a simple diagram showing (a) magnetic field lines oriented out of the page, and (b)
magnetic field line oriented into the page.
21-2
6. Draw a labeled diagram showing the first right-hand rule (for a straight wire with current).
7. Draw a labeled diagram showing the second right-hand rule (for a solenoid).
8. What causes elements like Fe, Co, and Ni to be magnetic?
9. Magnets generally lose their magnetism when heated. Considering domains, why does this
occur?
22-3
10. Draw a labeled diagram showing the third right-hand rule (for a charged particle moving
perpendicular to a magnetic field).
11. A uniform 1.5 T magnetic field points north. If an electron moves vertically downward (toward
the ground) with a speed of 2.5 x107 m/s through this field, what force (magnitude and
direction) will act on it?
12. A proton moves perpendicular to a magnetic field that has a magnitude of 4.20 x10-2 T. What is
the speed of the particle if the magnitude of the magnetic force is 2.40 x10-14 N?
13. Draw a diagram showing why an electron moving perpendicular to a magnetic field would follow
a circular path.
14. A 6.0 m wire carries a current of 7.0 A toward the +x direction. A magnetic force of 7.0 x10-6 N
acts on the wire in the –y direction. Find the magnitude and direction of the magnetic field
producing the force.
15. The magnetic force on a straight 0.15 m segment of wire carrying a current of 4.5 A is 1.0 N.
What is the magnitude of the component of the magnetic field that is perpendicular to the wire?
Answers: (11) 6.0 x10-12 N west, (12) 3.57 x106 m/s, (14) 1.7 x10-7 T in the +z direction, (15) 1.5 T.