1. © 2012 Pearson Education, Inc. { Chapter 28 Sources of Magnetic Field (cont.)

2. © 2012 Pearson Education, Inc. The long, straight wire AB carries a 14.0-A current as shown. The rectangular loop has long edges parallel to AB and carries a clockwise 5.00-A current. What is the direction of the net magnetic force that the straight wire AB exerts on the loop? Q28.5 A.to the right B.to the left C. upward (toward AB) D. downward (away from AB) E. The net magnetic force is zero

3. © 2012 Pearson Education, Inc. A28.5 The long, straight wire AB carries a 14.0-A current as shown. The rectangular loop has long edges parallel to AB and carries a clockwise 5.00-A current. What is the direction of the net magnetic force that the straight wire AB exerts on the loop? A.to the right B.to the left C. upward (toward AB) D. downward (away from AB) E. The net magnetic force is zero

4. © 2012 Pearson Education, Inc. Q28.6 A wire consists of two straight sections with a semicircular section between them. If current flows in the wire as shown, what is the direction of the magnetic field at P due to the current? A.to the right B.to the left C. out of the plane of the figure D. into the plane of the figure E. misleading question—the magnetic field at P is zero

5. © 2012 Pearson Education, Inc. A wire consists of two straight sections with a semicircular section between them. If current flows in the wire as shown, what is the direction of the magnetic field at P due to the current? A28.6 A.to the right B.to the left C. out of the plane of the figure D. into the plane of the figure E. misleading question—the magnetic field at P is zero

6. © 2012 Pearson Education, Inc. The wire shown here is infinitely long and has a 90° bend. If current flows in the wire as shown, what is the direction of the magnetic field at P due to the current? Q28.7 A.to the right B.to the left C. out of the plane of the figure D. into the plane of the figure E. none of these

7. © 2012 Pearson Education, Inc. The wire shown here is infinitely long and has a 90° bend. If current flows in the wire as shown, what is the direction of the magnetic field at P due to the current? A28.7 A.to the right B.to the left C. out of the plane of the figure D. into the plane of the figure E. none of these

8. © 2012 Pearson Education, Inc. Q28.8 The figure shows, in cross section, three conductors that carry currents perpendicular to the plane of the figure. If the currents I 1, I 2, and I 3 all have the same magnitude, for which path(s) is the line integral of the magnetic field equal to zero? A.path a only B.paths a and c C.paths b and d D.paths a, b, c, and d E.The answer depends on whether the integral goes clockwise or counterclockwise around the path.

9. © 2012 Pearson Education, Inc. The figure shows, in cross section, three conductors that carry currents perpendicular to the plane of the figure. If the currents I 1, I 2, and I 3 all have the same magnitude, for which path(s) is the line integral of the magnetic field equal to zero? A28.8 A.path a only B.paths a and c C.paths b and d D.paths a, b, c, and d E.The answer depends on whether the integral goes clockwise or counterclockwise around the path.

10. © 2012 Pearson Education, Inc. Paramagnetism, Diamagnetism, Ferromagnetism

11. © 2012 Pearson Education, Inc. Hysteresis in Ferromagnetic Materials

12. © 2012 Pearson Education, Inc. { Chapter 29 Electromagnetic Induction

13. © 2012 Pearson Education, Inc. Induced current  A changing magnetic flux causes an induced current. See Figure 29.1 below.  The induced emf is the corresponding emf causing the current.

14. © 2012 Pearson Education, Inc. Magnetic flux through an area element  Figure 29.3 below shows how to calculate the magnetic flux through an element of area.

15. © 2012 Pearson Education, Inc. Direction of the induced emf Follow the text discussion on the direction of the induced emf, using Figure 29.6 below. Follow the text discussion on the direction of the induced emf, using Figure 29.6 below.

16. © 2012 Pearson Education, Inc. A circular loop of wire is in a region of spatially uniform magnetic field. The magnetic field is directed into the plane of the figure. If the magnetic field magnitude is constant, Q29.1 A. the induced emf is clockwise. B. the induced emf is counterclockwise. C. the induced emf is zero. D. The answer depends on the strength of the field.

17. © 2012 Pearson Education, Inc. A circular loop of wire is in a region of spatially uniform magnetic field. The magnetic field is directed into the plane of the figure. If the magnetic field magnitude is constant, A29.1 A. the induced emf is clockwise. B. the induced emf is counterclockwise. C. the induced emf is zero. D. The answer depends on the strength of the field.