Ch32 Full Test Bank Maxwell’s Equations; Magnetism Of Matter - Physics Extended 11e | Test Bank by Halliday by David Halliday. DOCX document preview.
Chapter: Chapter 32
Learning Objectives
LO 32.1.0 Solve problems related to Gauss’ law for magnetic fields.
LO 32.1.1 Identify that the simplest magnetic structure is a magnetic dipole.
LO 32.1.2 Calculate the magnetic flux Φ through a surface by integrating the dot product of the magnetic field vector and the area vector (for patch elements) over the surface.
LO 32.1.3 Identify that the net magnetic flux through a Gaussian surface (which is a closed surface) is zero.
LO 32.2.0 Solve problems related to induced magnetic fields.
LO 32.2.1 Identify that a changing electric flux induces a magnetic field.
LO 32.2.2 Apply Maxwell’s law of induction to relate the magnetic field induced around a closed loop to the rate of change of electric flux encircled by the loop.
LO 32.2.3 Draw the field lines for an induced magnetic field inside a capacitor with parallel circular plates that are being charged, indicating the orientations of the vectors for the electric field and the magnetic field.
LO 32.2.4 For the general situation in which magnetic fields can be induced, apply the Ampere–Maxwell (combined) law.
LO 32.3.0 Solve problems related to displacement current.
LO 32.3.1 Identify that in the Ampere–Maxwell law, the contribution to the induced magnetic field by the changing electric flux can be attributed to a fictitious current (“displacement current”) to simplify the expression.
LO 32.3.2 Identify that in a capacitor that is being charged or discharged, a displacement current is said to be spread uniformly over the plate area, from one plate to the other.
LO 32.3.3 Apply the relationship between the rate of change of an electric flux and the associated displacement current.
LO 32.3.4 For a charging or discharging capacitor, relate the amount of displacement current to the amount of actual current and identify that the displacement current exists only when the electric field within the capacitor is changing.
LO 32.3.5 Mimic the equations for the magnetic field inside and outside a wire with real current to write (and apply) the equations for the magnetic field inside and outside a region of displacement current.
LO 32.3.6 Apply the Ampere–Maxwell law to calculate the magnetic field of a real current and a displacement current.
LO 32.3.7 For a charging or discharging capacitor with parallel circular plates, draw the magnetic field lines due to the displacement current.
LO 32.3.8 List Maxwell’s equations and the purpose of each.
LO 32.4.0 Solve problems related to magnets.
LO 32.4.1 Identify lodestones.
LO 32.4.2 In Earth’s magnetic field, identify that the field is approximately that of a dipole and also identify in which hemisphere the north geomagnetic pole is located.
LO 32.4.3 Identify field declination and field inclination.
LO 32.5.0 Solve problems related to magnetism and electrons.
LO 32.5.1 Identify that a spin angular momentum (usually simply called spin) and a spin magnetic dipole moment are intrinsic properties of electrons (and also protons and neutrons).
LO 32.5.2 Apply the relationship between the spin vector and the magnetic dipole moment vector .
LO 32.5.3 Identify that and cannot be observed (measured), only their components on an axis of measurement (usually called the z axis) can be observed.
LO 32.5.4 Identify that the observed components Sz and μS,Z are quantized and explain what that means.
LO 32.5.5 Apply the relationship between the component Sz and the spin magnetic quantum number ms, specifying the allowed values of ms.
LO 32.5.6 Distinguish spin up from spin down.
LO 32.5.7 Determine the z components μS,Z of the magnetic dipole moment, both as a value and in terms of the Bohr magneton μB.
LO 32.5.8 If an electron is in an external magnetic field, determine the orientation energy U of its spin magnetic dipole moment .
LO 32.5.9 Identify that an electron in an atom has an orbital angular momentum and an orbital magnetic dipole moment .
LO 32.5.10 Apply the relationship between the orbital angular momentum and the orbital magnetic dipole moment .
LO 32.5.11 Identity that and cannot be observed but their components and on a z (measurement) axis can.
LO 32.5.12 Apply the relationship between the component of the orbital angular momentum and the orbital magnetic quantum number mℓ, specifying the allowed values mℓ.
LO 32.5.13 Determine the z components of the magnetic dipole moment, both as a value and in terms of the Bohr magneton μB.
LO 32.5.14 If an atom is in an external magnetic field, determine the orientation energy U of the orbital magnetic dipole moment μorb.
LO 32.5.15 Calculate the magnitude of the magnetic moment of a charged particle moving in a circle or a ring of uniform charge rotating like a merry-go-round.
LO 32.5.16 Explain the classical loop model for an orbiting electron and the forces on such a loop in a nonuniform magnetic field.
LO 32.5.17 Distinguish diamagnetism, paramagnetism, and ferromagnetism.
LO 32.6.0 Solve problems related to diamagnetism.
LO 32.6.1 For a diamagnetic sample placed in an external magnetic field, identify that the field produces a magnetic dipole moment in the sample, and identify the relative orientations of that moment and the field.
LO 32.6.2 For a diamagnetic sample in a nonuniform magnetic field, describe the force on the sample and the resulting motion.
LO 32.7.0 Solve problems related to paramagnetism.
LO 32.7.1 For a paramagnetic sample placed in an external magnetic field, identify the relative orientations of the field and the sample’s magnetic dipole moment.
LO 32.7.2 For a paramagnetic sample in a nonuniform magnetic field, describe the force on the sample and the resulting motion.
LO 32.7.3 Apply the relationship between a sample’s magnetization M, its measured magnetic moment, and its volume.
LO 32.7.4 Apply Curie’s law to relate a sample’s magnetization M to its temperature T, its Curie constant C, and the magnitude B of the external field.
LO 32.7.5 Given a magnetization curve for a paramagnetic sample, relate the extent of the magnetization for a given magnetic field and temperature.
LO 32.7.6 For a paramagnetic sample at a given temperature and in a given magnetic field, compare the energy associated with the dipole orientations and the thermal motion.
LO 32.8.0 Solve problems related to ferromagnetism.
LO 32.8.1 Identify that ferromagnetism is due to a quantum mechanical interaction called exchange coupling.
LO 32.8.2 Explain why ferromagnetism disappears when the temperature exceeds the material’s Curie temperature.
LO 32.8.3 Apply the relationship between the magnetization of a ferromagnetic sample and the magnetic moment of its atoms.
LO 32.8.4 For a ferromagnetic sample at a given temperature and in a given magnetic field, compare the energy associated with the dipole orientations and the thermal motion.
LO 32.8.5 Describe and sketch a Rowland ring.
LO 32.8.6 Identify magnetic domains.
LO 32.8.7 For a ferromagnetic sample placed in an external magnetic field, identify the relative orientations of the field and the magnetic dipole moment.
LO 32.8.8 Identify the motion of a ferromagnetic sample in a nonuniform field.
LO 32.8.9 For a ferromagnetic object placed in a uniform magnetic field, calculate the torque and orientation energy.
LO 32.8.10 Explain hysteresis and a hysteresis loop.
LO 32.8.11 Identify the origin of lodestones.
Multiple Choice
1. Gauss' law for magnetism:
A) can be used to find due to given currents provided there is enough symmetry
B) is false because there are no magnetic poles
C) can be used with open surfaces because there are no magnetic poles
D) contradicts Faraday's law because one says B = 0 and the other says = –dB/dt
E) none of the above
Difficulty: E
Section: 32-1
Learning Objective 32.1.0
2. The statement that magnetic field lines form closed loops is a direct consequence of:
A) Faraday's law
B) Ampere's law
C) Gauss' law for electricity
D) Gauss' law for magnetism
E) the Lorentz force
Difficulty: E
Section: 32-1
Learning Objective 32.1.0
3. A magnetic field parallel to the x axis with a magnitude that decreases with increasing x but does not change with y and z is impossible according to:
A) Faraday's law
B) Ampere's law
C) Gauss' law for electricity
D) Gauss' law for magnetism
E) Newton's second law
Difficulty: E
Section: 32-1
Learning Objective 32.1.0
4. According to Gauss' law for magnetism, magnetic field lines:
A) form closed loops
B) start at south poles and end at north poles
C) start at north poles and end at south poles
D) start at both north and south poles and end at infinity
E) do not exist
Difficulty: E
Section: 32-1
Learning Objective 32.1.0
5. Gauss' law for magnetism, , tells us:
A) the net charge in any given volume
B) that the line integral of a magnetic field around any closed loop must vanish
C) the magnetic field of a current element
D) that magnetic monopoles do not exist
E) charges must be moving to produce magnetic fields
Difficulty: E
Section: 32-1
Learning Objective 32.1.1
6. Four closed surfaces are shown, each with circular top and bottom faces and curved sides. The areas Atop and Abot of the top and bottom faces and the magnitudes Btop and Bbot of the uniform magnetic fields through the top and bottom faces are given. The fields are perpendicular to the faces and are either inward or outward. Rank the surfaces according to the magnitude of the magnetic flux through the curved sides, least to greatest.
A) 1, 2, 3, 4
B) 3, 4, 1, 2
C) 1, 2, 4, 3
D) 4, 3, 2, 1
E) 2, 1, 4, 3
Difficulty: M
Section: 32-1
Learning Objective 32.1.3
7. A 1-A current is used to charge a parallel plate capacitor. A large square piece of paper is placed between the plates and parallel to them so it sticks out on all sides. The value of the integral around the perimeter of the paper is:
A) 2 Tm
B) 4 10–7 Tm
C) 8.85 10–12 Tm
D) 10–7 Tm
E) not determined from the given quantities
Difficulty: M
Section: 32-2
Learning Objective 32.2.0
8. A magnetic field exists between the plates of a capacitor:
A) always
B) never
C) when the capacitor is fully charged
D) while the capacitor is being charged
E) only when the capacitor is starting to be charged
Difficulty: E
Section: 32-2
Learning Objective 32.2.1
9. A cylindrical region contains a uniform electric field that is along the cylinder axis and is changing with time. If r is the distance from the cylinder axis the magnitude of the magnetic field within the region is:
A) uniform
B) proportional to 1/r
C) proportional to r2
D) proportional to 1/r2
E) proportional to r
Difficulty: E
Section: 32-2
Learning Objective 32.2.2
10. A cylindrical region contains a uniform electric field that is parallel to the axis and is changing with time. If r is the distance from the cylinder axis the magnitude of the magnetic field outside the region is:
A) zero
B) proportional to 1/r
C) proportional to r2
D) proportional to 1/r2
E) proportional to r
Difficulty: E
Section: 32-2
Learning Objective 32.2.2
11. A 0.70-m radius cylindrical region contains a uniform electric field that is parallel to the axis and is increasing at the rate 5.0 1012 V/ms. The magnetic field at a point 0.25 m from the axis has a magnitude of:
A) 0 T
B) 7.0 10–6 T
C) 2.8 10–5 T
D) 5.4 10–5 T
E) 7.0 10–5 T
Difficulty: M
Section: 32-2
Learning Objective 32.2.2
12. A 0.70-m radius cylindrical region contains a uniform electric field that is parallel to the axis and is increasing at the rate 5.0 1012 V/ms. The magnetic field at a point 1.2 m from the axis has a magnitude of:
A) 0 T
B) 7.0 10–6 T
C) 1.1 10–5 T
D) 2.3 10–5 T
E) 2.8 10–5 T
Difficulty: M
Section: 32-2
Learning Objective 32.2.2
13. A sinusoidal emf is connected to a parallel plate capacitor. The magnetic field between the plates is:
A) zero
B) constant
C) sinusoidal and its amplitude does not depend on the frequency of the source
D) sinusoidal and its amplitude is proportional to the frequency of the source
E) sinusoidal and its amplitude is inversely proportional to the frequency of the source
Difficulty: M
Section: 32-2
Learning Objective 32.2.2
14. An electric field exists in the cylindrical region shown and is parallel to the cylinder axis. The magnitude of the field might vary with time according to any of the four graphs shown. Rank the four variations according to the magnitudes of the magnetic field induced at the edge of the region, least to greatest.
A) 2, 4, 3, 1
B) 1, 3, 4, 2
C) 4, 3, 2, 1
D) 4, 3, 1, 2
E) 2, 1, 3, 4
Difficulty: E
Section: 32-2
Learning Objective 32.2.2
15. The diagram shows one plate of a parallel-plate capacitor from within the capacitor. The plate is circular and has radius R. The dashed circles are four integration paths have radii of r1 = R/4, r2 = R/2, r3 =3 R/2, and r4 = 2R. Rank the paths according to the magnitude of around the paths during the discharging of the capacitor, least to greatest.
A) 1, 2 and 3 tie, then 4
B) 1, 2, 3, 4
C) 1, then 2 and 4 tie, then 3
D) 4, 3, 1, 2
E) 3, then 2 and 4 tie, then 1
Difficulty: M
Section: 32-2
Learning Objective 32.2.2
16. Suppose you are looking into one end of a long cylindrical tube in which there is a uniform electric field, pointing away from you. If the magnitude of the field is decreasing with time the direction of the induced magnetic field is:
A) toward you
B) away from you
C) clockwise
D) counterclockwise
E) to your right
Difficulty: E
Section: 32-2
Learning Objective 32.2.4
17. Suppose you are looking into one end of a long cylindrical tube in which there is a uniform electric field, pointing away from you. If the magnitude of the field is decreasing with time the field lines of the induced magnetic field are:
A) circles
B) ellipses
C) straight lines parallel to the electric field
D) straight lines perpendicular to the electric field
E) none of the above
Difficulty: E
Section: 32-2
Learning Objective 32.2.4
18. An electron is on the z axis moving toward the xy plane but it has not reached that plane yet. At that instant:
A) there is only a true current through the xy plane
B) there is only a displacement current through the xy plane
C) there are both true and displacement currents through the xy plane
D) there is neither a true nor a displacement current through the xy plane
E) none of the above are true
Difficulty: E
Section: 32-3
Learning Objective 32.3.0
19. One of the Maxwell equations begins with .... The symbol me
Difficulty: E
Section: 32-3
Learning Objective 32.3.0
20. One of the Maxwell equations begins with .... The o symbol in the integral sign me
Difficulty: E
Section: 32-3
Learning Objective 32.3.0
21. One of the Maxwell equations begins with .... The o symbol in the integral sign me
Difficulty: E
Section: 32-3
Learning Objective 32.3.0
22. Two of Maxwell's equations contain a path integral on the left side and an area integral on the right. For them:
A) the path must pierce the area
B) the path must be well-separated from the area
C) the path must be along a field line and the area must be perpendicular to the field line
D) the path must be the boundary of the area
E) the path must lie in the area, away from its boundary
Difficulty: E
Section: 32-3
Learning Objective 32.3.0
23. Two of Maxwell's equations contain an integral over a closed surface. For them the infinitesimal vector area is always:
A) tangent to the surface
B) perpendicular to the surface and pointing outward
C) perpendicular to the surface and pointing inward
D) tangent to a field line
E) perpendicular to a field line
Difficulty: E
Section: 32-3
Learning Objective 32.3.0
24. Two of Maxwell's equations contain a path integral on the left side and an area integral on the right. The directions of the infinitesimal path element and infinitesimal area element are:
A) always in the same direction
B) always in opposite directions
C) always perpendicular to each other
D) never perpendicular to each other
E) none of the above
Difficulty: E
Section: 32-3
Learning Objective 32.3.0
25. Two of Maxwell's equations contain a path integral on the left side and an area integral on the right. Suppose the area is the surface of a piece of paper at which you are looking and is chosen to point toward you. Then, the path integral is:
A) clockwise around the circumference of the paper
B) counterclockwise around the circumference of the paper
C) from left to right
D) from right to left
E) from top to bottom
Difficulty: E
Section: 32-3
Learning Objective 32.3.0
26. A 1.2-m radius cylindrical region contains a uniform electric field along the cylinder axis. It is increasing uniformly with time. To obtain a total displacement current of 2.0 109 A through a cross section of the region, the magnitude of the electric field should change at a rate of:
A) 5.0 V/m·s
B) 12 V/m·s
C) 37 V/m·s
D) 50 V/m·s
E) 4.0 107 V/m·s
Difficulty: M
Section: 32-3
Learning Objective 32.3.3
27. A 1-F capacitor is connected to an emf that is increasing uniformly with time at a rate of 100 V/s. The displacement current between the plates is:
A) 0 A
B) 1 10–8 A
C) 1 10–6 A
D) 1 10–4 A
E) 100 A
Difficulty: M
Section: 32-3
Learning Objective 32.3.3
28. Displacement current is:
A) dE/dt
B) 0dE/dt
C) 0dE/dt
D) 00dE/dt
E) –dB/dt
Difficulty: E
Section: 32-3
Learning Objective 32.3.3
29. Displacement current exists wherever there is:
A) moving charge
B) a magnetic field
C) a changing magnetic field
D) an electric field
E) a changing electric field
Difficulty: E
Section: 32-3
Learning Objective 32.3.3
30. A current of 1 A is used to charge a parallel plate capacitor with square plates. If the area of each plate is 0.6 m2 the displacement current through a 0.3 m2 area wholly between the capacitor plates and parallel to them is:
A) 2 A
B) 1 A
C) 0.7 A
D) 0.5 A
E) 0.25 A
Difficulty: M
Section: 32-3
Learning Objective 32.3.4
31. Displacement current exists in the region between the plates of a parallel plate capacitor if:
A) the capacitor leaks charge across the plates
B) the capacitor is being discharged
C) the capacitor is fully charged
D) the capacitor is fully discharged
E) none of the above are true
Difficulty: E
Section: 32-3
Learning Objective 32.3.4
32. A circular parallel-plate capacitor whose plates have a radius of 25 cm is being charged with a current of 1.3 A. What is the magnetic field 11 cm from the center of the plates?
A) 4.6 x 10-7 T
B) 1.0 x 10-6 T
C) 2.4 x 10-6 T
D) 3.1 x 10-6 T
E) 6.2 x 10-6 T
Difficulty: M
Section: 32-3
Learning Objective 32.3.6
33. Consider the four Maxwell equations:
I. | |||
II. | |||
III. | |||
IV. |
Which of these must be modified if magnetic poles are discovered?
A) only I
B) only II
C) only II and III
D) only III and IV
E) only II, III, IV
Difficulty: E
Section: 32-3
Learning Objective 32.3.8
34. One of the crucial facts upon which the Maxwell equations are based is:
A) the numerical value of the electron charge
B) charge is quantized
C) the numerical value of the charge/mass ratio of the electron
D) there are three types of magnetic materials
E) none of the above
Difficulty: E
Section: 32-3
Learning Objective 32.3.8
35. Which of the following equations can be used, along with a symmetry argument, to calculate the electric field of a point charge?
A)
B)
C)
D)
E) none of these
Difficulty: E
Section: 32-3
Learning Objective 32.3.8
36. Which of the following equations can be used, along with a symmetry argument, to calculate the magnetic field of a long straight wire carrying current?
A)
B)
C)
D)
E) none of these
Difficulty: E
Section: 32-3
Learning Objective 32.3.8
37. Which of the following equations can be used to show that magnetic field lines form closed loops?
A)
B)
C)
D)
E) none of these
Difficulty: E
Section: 32-3
Learning Objective 32.3.8
38. Which of the following equations, along with a symmetry argument, can be used to calculate the magnetic field produced by a uniform time-varying electric field?
A)
B)
C)
D)
E) none of these
Difficulty: E
Section: 32-3
Learning Objective 32.3.8
39. Which of the following equations, along with a symmetry argument, can be used to calculate the electric field produced by a uniform time-varying magnetic field?
A)
B)
C)
D)
E) none of these
Difficulty: E
Section: 32-3
Learning Objective 32.3.8
40. Which of the following equations, along with a symmetry argument, can be used to calculate the magnetic field between the plates of a charging parallel plate capacitor with circular plates?
A)
B)
C)
D)
E) none of these
Difficulty: E
Section: 32-3
Learning Objective 32.3.8
41. Maxwell's equations, along with an appropriate symmetry argument, can be used to calculate:
A) the electric force on a given charge
B) the magnetic force on a given moving charge
C) the flux of a given electric field
D) the flux of a given magnetic field
E) none of these
Difficulty: E
Section: 32-3
Learning Objective 32.3.8
42. The magnetic field of Earth is roughly the same as that of a magnetic dipole with a dipole moment of about:
A) 1017 J/T
B) 1019 J/T
C) 1021 J/T
D) 1023 J/T
E) 1025 J/T
Difficulty: E
Section: 32-4
Learning Objective 32.4.0
43. Of the following places one would expect that the horizontal component of the Earth's magnetic field to be largest in:
A) Maine
B) Florida
C) Maryland
D) New York
E) Iowa
Difficulty: E
Section: 32-4
Learning Objective 32.4.0
44. A positively charged ion, due to a cosmic ray, is headed through Earth's atmosphere toward the center of Earth. Due to Earth's magnetic field, the ion will be deflected:
A) south
B) north
C) west
D) east
E) not at all since it is a charge and not a pole
Difficulty: E
Section: 32-4
Learning Objective 32.4.0
45. The polarity of an unmarked magnet can be determined using:
A) a charged glass rod
B) a compass
C) an electroscope
D) another unmarked magnet
E) iron filings
Difficulty: E
Section: 32-4
Learning Objective 32.4.0
46. A bar magnet is placed vertically with its S pole up and its N pole down. The field at its center is:
A) zero
B) down
C) up
D) horizontal
E) slightly below the horizontal
Difficulty: E
Section: 32-4
Learning Objective 32.4.0
47. A bar magnet is broken in half. Each half is broken in half again, etc. The observation is that each piece has both a north and south pole. This is usually explained by:
A) Ampere's theory that all magnetic phenomena result from electric currents
B) our inability to divide the magnet into small enough pieces
C) Coulomb's law
D) Lenz' law
E) conservation of charge
Difficulty: E
Section: 32-4
Learning Objective 32.4.0
48. A small bar magnet is suspended horizontally by a string. When placed in a uniform horizontal magnetic field, it will:
A) translate in the direction of
B) translate in the opposite direction of
C) rotate so as to be at right angles to
D) rotate so as to be vertical
E) none of the above
Difficulty: E
Section: 32-4
Learning Objective 32.4.0
49. Magnetic dipole X is fixed and dipole Y is free to move. Dipole Y will initially:
A) move toward X but not rotate
B) move away from X but not rotate
C) move toward X and rotate
D) move away from X and rotate
E) rotate but not translate
Difficulty: E
Section: 32-4
Learning Objective 32.4.0
50. Magnetic dipole X is fixed. Dipole Y is placed in the position indicated and is free to move. The first thing dipole Y will do is:
A) move toward X but not rotate
B) move away from X but not rotate
C) move toward X and rotate
D) move away from X and rotate
E) rotate but not move toward or away from X
Difficulty: E
Section: 32-4
Learning Objective 32.4.0
51. The potential energy of a magnetic dipole in an external magnetic field is least when:
A) the dipole moment is parallel to the field
B) the dipole moment is antiparallel to the field
C) the dipole moment is perpendicular to the field
D) none of the above (the same energy is associated with all orientations)
E) none of the above (no energy is associated with the dipole-field interaction)
Difficulty: E
Section: 32-4
Learning Objective 32.4.0
52. The magnetic field lines due to an ordinary bar magnet:
A) form closed curves
B) cross one another near the poles
C) are more numerous near the N pole than near the S pole
D) leave the S pole, loop around the outside of the magnet, and enter the N pole
E) none of the above
Difficulty: E
Section: 32-4
Learning Objective 32.4.0
53. Which of the following statements about the Earth’s magnetic field is correct?
A) The Earth’s magnetic field is approximately that of a dipole, and the north magnetic pole is in the northern hemisphere.
B) The Earth’s magnetic field is approximately that of a dipole, and the north magnetic pole is in the southern hemisphere.
C) The Earth’s magnetic field is approximately that of a monopole, and the north magnetic pole is in the northern hemisphere.
D) The Earth’s magnetic field is approximately that of a monopole, and the north magnetic pole is in the southern hemisphere.
E) The Earth’s magnetic field is approximately that of a quadrupole, and the north magnetic pole is in the eastern hemisphere.
Difficulty: E
Section: 32-4
Learning Objective 32.4.2
54. Which of the following statements is correct?
A) The declination of the Earth’s magnetic field is the angle between a horizontal plane and the direction of the field.
B) The declination of the Earth’s magnetic field is the angle between a vertical plane and the direction of the field.
C) The inclination of the Earth’s magnetic field is the angle between a horizontal plane and the direction of the field.
D) The inclination of the Earth’s magnetic field is the angle between the horizontal component of the field direction and the direction to geographic north.
E) Inclination and declination mean the same thing.
Difficulty: E
Section: 32-4
Learning Objective 32.4.3
55. An electron traveling with speed v around a circle of radius r is equivalent to a current of:
A) evr/2
B) ev/r
C) ev/2r
D) 2er/v
E) 2ev/r
Difficulty: E
Section: 32-5
Learning Objective 32.5.0
56. The molecular theory of magnetism can explain each of the following EXCEPT:
A) a N pole attracts a S pole
B) stroking an iron bar with a magnet will magnetize the bar
C) when a bar magnet is broken in two, each piece is a bar magnet
D) heating tends to destroy magnetization
E) hammering tends to destroy magnetization
Difficulty: E
Section: 32-5
Learning Objective 32.5.0
57. The magnetic properties of materials stem chiefly from:
A) particles with north poles
B) particles with south poles
C) motions of protons within nuclei
D) proton spin angular momentum
E) electron magnetic dipole moments
Difficulty: E
Section: 32-5
Learning Objective 32.5.0
58. The spin magnetic dipole moment of an electron:
A) is in the same direction as the spin angular momentum
B) is zero
C) has a magnitude that depends on the orbital angular momentum
D) has a magnitude that depends on the applied magnetic field
E) none of the above
Difficulty: E
Section: 32-5
Learning Objective 32.5.2
59. Which of the following statements is correct?
A) The spin angular momentum of the electron can be directly observed, but the spin magnetic dipole moment cannot be.
B) The spin angular momentum of the electron cannot be directly observed, but the spin magnetic dipole moment can be.
C) Both the spin angular momentum and the spin magnetic dipole moment of the electron can be directly observed.
D) Neither the spin angular momentum nor the spin magnetic dipole moment of the electron can be directly observed.
E) Although both the spin angular momentum and the spin magnetic dipole moment can be defined theoretically, neither has any physical meaning at all.
Difficulty: E
Section: 32-5
Learning Objective 32.5.3
60. What are the possible allowed values of the spin magnetic quantum number ms of the electron?
A) +1/2 only
B) ±1/2
C) any half-odd integer
D) any integer
E) It depends on the external magnetic field.
Difficulty: E
Section: 32-5
Learning Objective 32.5.5
61. If an electron has zero orbital angular momentum, the magnitude of its magnetic dipole moment equals:
A) zero
B) half the Bohr magneton
C) a Bohr magneton
D) twice a Bohr magneton
E) none of these
Difficulty: E
Section: 32-5
Learning Objective 32.5.7
62. The magnetic dipole moment of an atomic electron is typically:
A) much less than a Bohr magneton
B) a few Bohr magnetons
C) much greater than a Bohr magneton
D) much greater or much less than a Bohr magneton, depending on the atom
E) not related to the value of the Bohr magneton
Difficulty: E
Section: 32-5
Learning Objective 32.5.7
63. The magnitude of the Bohr magneton is about:
A) 10–15 J/T
B) 10–19 J/T
C) 10–23 J/T
D) 10–27 J/T
E) 10–31 J/T
Difficulty: E
Section: 32-5
Learning Objective 32.5.7
64. The diagram shows the spin angular momentum vectors of two electrons and two protons in the same external magnetic field. The field points upward in the diagram. Rank the situations according to the potential energy, least to greatest.
A) 1 and 3 tie, then 2 and 4 tie
B) 2 and 3 tie, then 1 and 4 tie
C) 1 and 2 tie, then 3 and 4 tie
D) 3 and 4 tie, then 1 and 2 tie
E) all tie
Difficulty: E
Section: 32-5
Learning Objective 32.5.8
65. If is the orbital angular momentum of an electron, the magnetic dipole moment associated with its orbital motion:
A) is in the direction of and has magnitude proportional to L
B) is opposite to the direction of and has magnitude proportional to L
C) is in the direction of and has magnitude proportional to L2
D) is opposite to the direction of and has magnitude proportional to L2
E) does not depend on
Difficulty: E
Section: 32-5
Learning Objective 32.5.10
66. If an electron has an orbital angular momentum with magnitude L the magnitude of the orbital contribution to its magnetic dipole moment is given by:
A) eL/m
B) eL/2m
C) 2eL/m
D) mL/e
E) mL/2
Difficulty: E
Section: 32-5
Learning Objective 32.5.10
67. The intrinsic magnetic dipole moments of protons and neutrons are much less than that of an electron because:
A) their masses are greater
B) their angular momenta are much less
C) their angular momenta are much greater
D) their charges are much less
E) their radii are much less
Difficulty: E
Section: 32-5
Learning Objective 32.5.10
68. What are the possible allowed values of the orbital magnetic quantum number mℓ of the electron?
A) 0 only
B) 0, ±1 only
C) any half-odd integer
D) 0, ±1, ±2, …, up to the maximum value for that orbit
E) It depends on the external magnetic field.
Difficulty: E
Section: 32-5
Learning Objective 32.5.12
69. An electron in a hydrogen atom moves in a circle of radius 1.1 x 10-10 m at a speed of about 1.6 x 106 m/s. What is the magnetic dipole moment of this electron due to its orbital motion?
A) 9.3 x 10-24 J/T
B) 1.4 x 10-23 J/T
C) 1.9 x 10-23 J/T
D) 2.8 x 10-23 J/T
E) 3.5 x 10-23 J/T
Difficulty: M
Section: 32-5
Learning Objective 32.5.15
70. Lenz' law can explain:
A) paramagnetism only
B) diamagnetism only
C) ferromagnetism only
D) only two of the three types of magnetism
E) all three of the types of magnetism
Difficulty: E
Section: 32-6
Learning Objective 32.6.0
71. A magnetic field is applied to a diamagnetic substance. In the interior the magnetic field produced by the magnetic dipoles of the substance is:
A) greater than and in the opposite direction
B) less than and in the opposite direction
C) greater than and in the same direction
D) less than and in the same direction
E) the same as
Difficulty: E
Section: 32-6
Learning Objective 32.6.1
72. The diagram shows two small diamagnetic spheres, one near each end of a bar magnet. Which of the following statements is true?
A) The force on 1 is toward the magnet and the force on 2 is away from the magnet
B) The force on 1 is away from the magnet and the force on 2 is away from the magnet
C) The forces on 1 and 2 are both toward the magnet
D) The forces on 1 and 2 are both away from the magnet
E) The magnet does not exert a force on either sphere
Difficulty: E
Section: 32-6
Learning Objective 32.6.1
73. The units of magnetization are:
A) ampere
B) amperemeter
C) amperemeter2
D) ampere/meter
E) ampere/meter2
Difficulty: E
Section: 32-7
Learning Objective 32.7.0
74. A paramagnetic substance, in an external magnetic field, is thermally isolated. The field is then removed. As a result:
A) the magnetic energy of the magnetic dipoles decreases
B) the temperature of the substance increases
C) the magnetization decreases, but only slightly
D) the magnetization reverses direction
E) none of the above
Difficulty: E
Section: 32-7
Learning Objective 32.7.0
75. Paramagnetism is closely associated with:
A) the tendency of electron dipole moments to align with an applied magnetic field
B) the tendency of electron dipole moments to align opposite to an applied magnetic field
C) the exchange force between electrons
D) the force exerted by electron dipole moments on each other
E) the torque exerted by electron dipole moments on each other
Difficulty: E
Section: 32-7
Learning Objective 32.7.1
76. The diagram shows two small paramagnetic spheres, one near each end of a bar magnet. Which of the following statements is true?
A) The force on 1 is toward the magnet and the force on 2 is away from the magnet
B) The force on 1 is away from the magnet and the force on 2 is away from the magnet
C) The forces on 1 and 2 are both toward the magnet
D) The forces on 1 and 2 are both away from the magnet
E) The magnet does not exert a force on either sphere
Difficulty: E
Section: 32-7
Learning Objective 32.7.1
77. A magnetic field is applied to a paramagnetic substance. In the interior the magnetic field produced by the magnetic dipoles of the substance is:
A) greater than and in the opposite direction
B) less than and in the opposite direction
C) greater than and in the same direction
D) less than and in the same direction
E) the same as
Difficulty: E
Section: 32-7
Learning Objective 32.7.1
78. Magnetization is:
A) the current density in an object
B) the charge density of moving charges in an object
C) the magnetic dipole moment of an object
D) the magnetic dipole moment per unit volume of an object
E) the magnetic field per unit volume produced by an object
Difficulty: E
Section: 32-7
Learning Objective 32.7.3
79. A paramagnetic substance is placed in a weak magnetic field and its absolute temperature T is increased. As a result, its magnetization:
A) increases in proportion to T
B) increases in proportion to T2
C) remains the same
D) decreases in proportion to 1/T
E) decreases in proportion to 1/T2
Difficulty: E
Section: 32-7
Learning Objective 32.7.4
80. The soft iron core in the solenoid shown is removable. Then:
A) the current will be larger without the core
B) the current will be larger with the core
C) one must do work to remove the core
D) the circuit will do work in expelling the core
E) the stored energy is the same with or without the core
Difficulty: E
Section: 32-8
Learning Objective 32.8.0
81. When a permanent magnet is strongly heated:
A) nothing happens
B) it becomes an induced magnet
C) it loses its magnetism
D) its magnetism increases
E) its polarity reverses
Difficulty: E
Section: 32-8
Learning Objective 32.8.2
82. Ferromagnetism is closely associated with:
A) the tendency of electron dipole moments to align with an applied magnetic field
B) the tendency of electron dipole moments to align opposite to an applied magnetic field
C) the tendency of electron dipole moments to change magnitude in an applied magnetic field
D) the tendency of electron dipole moments to align with each other
E) the force exerted by electron dipole moments on each other
Difficulty: E
Section: 32-8
Learning Objective 32.8.3
83. Magnetization vectors in neighboring ferromagnetic domains are:
A) always in opposite directions
B) always in the same direction
C) always in different directions
D) sometimes in different directions and sometimes in the same direction
E) sometimes in opposite directions and sometimes in the same direction
Difficulty: E
Section: 32-8
Learning Objective 32.8.6
84. The behavior of ferromagnetic domains in an applied magnetic field gives rise to:
A) hysteresis
B) ferromagnetism
C) the Curie law
D) a lowering of the Curie temperature
E) Gauss' law for magnetism
Difficulty: E
Section: 32-8
Learning Objective 32.8.10
85. Because ferromagnets exhibit hysteresis, the magnetization:
A) can never be in the same direction as an applied field
B) may not vanish when an applied field is reduced to zero
C) can never vanish
D) is proportional to any applied magnetic field
E) is always opposite to the direction of any applied magnetic field
Difficulty: E
Section: 32-8
Learning Objective 32.8.10
86. An unmagnetized steel bar is placed inside a solenoid. As the current in the solenoid is slowly increased from zero to some large value, the magnetization of the bar:
A) increases proportionally with the current
B) remains zero for a while and then increases linearly with any further increase in current
C) increases with increasing current at first but later is much less affected by it
D) is unaffected by the current
E) increases quadratically with the current
Difficulty: E
Section: 32-8
Learning Objective 32.8.10
87. Of the three chief kinds of magnetic materials (diamagnetic, paramagnetic, and ferromagnetic) which are used to make permanent magnets?
A) only diamagnetic
B) only ferromagnetic
C) only paramagnetic
D) only paramagnetic and ferromagnetic
E) all three
Difficulty: E
Section: 32-8
Learning Objective 32.8.10