Question 1

A current is clockwise around the outside edge of this page and a uniform magnetic field is directed parallel to the page, from left to right. If the magnetic force is the only force acting on the page, the page will turn so the right edge:

Accepted Answer

A)   moves toward you
B)   moves away from you
C)   moves to your right
D)   moves to your left
E)   does not move

Question 2

A hydrogen atom that has lost its electron is moving east in a region where the magnetic field is directed from south to north. It will be deflected:

Accepted Answer

A)   up
B)   down
C)   north
D)   south
E)   not at all

Question 3

An electron is travelling in the positive x direction. A uniform electric field  is in the negative y direction. If a uniform magnetic field with the appropriate magnitude and direction also exists in the region, the total force on the electron will be zero. The appropriate direction for the magetic field is:

Accepted Answer

A)   the positive y direction
B)   the negative y direction
C)   into the page
D)   out of the page
E)   the negative x direction

Question 4

A loop of current-carrying wire has a magnetic dipole moment of 5 * 10-4 A . m2. The moment initially is aligned with a 0.5-T magnetic filed.To rotate the loop so its dipole momentt is perpendicular to the field and hold it in that orentation, you must do work of:

Accepted Answer

A)   0
B)   2.5* 10-4 J
C)   -2.5 * 10-4 J
D)   1.0 * 10-3 J
E)   -1.0 * 10-3 J

Question 5

An electron and a proton are both initially moving with the same speed and in the same direction at 90˚ to the same uniform magnetic field. They experience magnetic forces, which are initially:

Accepted Answer

A)   identical
B)   equal in magnitude but opposite in direction
C)   in the same direction and differing in magnitude by a factor of 1840
D)   in opposite directions and differing in magnitude by a factor of 1840
E)   equal in magnitude but perpendicular to each other

Question 6

An electron (charge = -1.6 * 10-19C)  is moving at 3 * 105 m/s in the positive x direction. A magnetic field of 0.8 T is in the positive z direction. The magnetic force on the electron is:

Accepted Answer

A)   0
B)   4 * 10-14 N in the positive z direction
C)   4 * 10-14 N in the negative z direction
D)   4 *10-14 N in the positive y direction
E)   4 * 10-14 N in the negative y direction

Question 7

The diagrams show five possible orientations of a magnetic dipole  in a uniform magnetic field  For which of these does the magnetic torque on the dipole have the greatest magnitude?

Accepted Answer

A)   I
B)   II
C)   III
D)   IV
E)   V

Question 8

The units of magnetic dipole moment are:

Accepted Answer

A)   ampere
B)   ampere .meter
C)   ampere .meter2
D)   ampere/meter
E)   ampere/meter2

Question 9

You are facing a loop of wire which carries a clockwise current of 3.0 A and which surrounds an area of 5.8 10−2m2. The magnetic dipole moment of the loop is:

Accepted Answer

A)   3.0 A. m2, into the page
B)   3.0 A . m2, out of the page
C)   0.17 A .m2, into the page
D)   0.17 A . m2, out of the page
E)   0.17 A .m2, left to right

Question 10

Electrons (mass m, charge -e)  are accelerated from rest through a potential difference V and are then deflected by a magnetic field  that is perpendicular to their velocity. The radius of the resulting electron trajectory is:

Accepted Answer

A)   
B)   
C)   
D)   
E)   none of these

Question 11

An electron moves in the negative x direction, through a uniform magnetic field in the negative y direction. The magnetic force on the electron is:

Accepted Answer

A)   in the negative x direction
B)   in the positive y direction
C)   in the negative y direction
D)   in the positive z direction
E)   in the negative z direction

Question 12

An electron enters a region of uniform perpendicular  fields. It is observed that the velocity  of the electron is unaffected. A possible explanation is:

Accepted Answer

A)    is parallel to  and has magnitude E/B
B)    is parallel to 
C)    is perpendicular to both  and has magnitude B/E
D)    is perpendicular to both  and has magnitude E/B
E)   the given situation is impossible

Question 13

A charged particle is projected into a region of uniform, parallel,  fields. The force on the particle is:

Accepted Answer

A)   zero
B)   at some angle 
C)   along the field lines
D)   perpendicular to the field lines
E)   unknown (need to know the sign of the charge)

Question 14

A uniform magnetic field is directed into the page. A charged particle, moving in the plane of the page, follows a clockwise spiral of decreasing radius as shown. A reasonable explanation is:

Accepted Answer

A)   the charge is positive and slowing down
B)   the charge is negative and slowing down
C)   the charge is positive and speeding up
D)   the charge is negative and speeding up
E)   none of the above

Question 15

A circular loop of wire with a radius of 20 cm lies in the xy plane and carries a current of 2 A, counterclockwise when viewed from a point on the positive z axis. Its magnetic dipole moment is:

Accepted Answer

A)   0.25 A . m2, in the positive z direction
B)   0.25 A .m2, in the negative z direction
C)   2.5 A .m2, in the positive z direction
D)   2.5 A .m2, in the negative z direction
E)   0.25 A . m2, in the xy plane

Question 16

The figure shows the motion of electrons in a wire which is near the N pole of a magnet. The wire will be pushed:

Accepted Answer

A)   toward the magnet
B)   away from the magnet
C)   downwards
D)   upwards
E)   along its length

Question 17

At any point the magnetic field lines are in the direction of:

Accepted Answer

A)   the magnetic force on a moving positive charge
B)   the magnetic force on a moving negative charge
C)   the velocity of a moving positive charge
D)   the velocity of a moving negative charge
E)   none of the above

Question 18

A magnetic field exerts a force on a charged particle:

Accepted Answer

A)   always
B)   never
C)   if the particle is moving across the field lines
D)   if the particle is moving along the field lines
E)   if the particle is at rest

Question 19

A loop of wire carrying a current of 2.0 A is in the shape of a right triangle with two equal sides, each 15 cm long. A 0.7 T uniform magnetic field is parallel to the hypotenuse. The resultant magnetic force on the two sides has a magnitude of:

Accepted Answer

A)   0
B)   0.21 N
C)   0.30 N
D)   0.41 N
E)   0.51 N

Question 20

An electron is moving north in a region where the magnetic field is south. The magnetic force exerted on the electron is:

Accepted Answer

A)   zero
B)   up
C)   down
D)   east
E)   west

Exam 28: Magnetic Fields

An electron enters a region of uniform perpendicular fields. It is observed that the velocity of the electron is unaffected. A possible explanation is:

Correct Answer
verified

An electron is moving north in a region where the magnetic field is south. The magnetic force exerted on the electron is:

Correct Answer
verified

The diagrams show five possible orientations of a magnetic dipole in a uniform magnetic field For which of these does the magnetic torque on the dipole have the greatest magnitude?

Correct Answer
verified

A hydrogen atom that has lost its electron is moving east in a region where the magnetic field is directed from south to north. It will be deflected:

Correct Answer
verified

At any point the magnetic field lines are in the direction of:

Correct Answer
verified

A loop of current-carrying wire has a magnetic dipole moment of 5 * 10^-⁴ A . m². The moment initially is aligned with a 0.5-T magnetic filed.To rotate the loop so its dipole momentt is perpendicular to the field and hold it in that orentation, you must do work of:

Correct Answer
verified

An electron (charge = -1.6 * 10^-¹⁹C) is moving at 3 * 10⁵ m/s in the positive x direction. A magnetic field of 0.8 T is in the positive z direction. The magnetic force on the electron is:

Correct Answer
verified

A magnetic field exerts a force on a charged particle:

Correct Answer
verified

A charged particle is projected into a region of uniform, parallel, fields. The force on the particle is:

Correct Answer
verified

Electrons (mass m, charge -e) are accelerated from rest through a potential difference V and are then deflected by a magnetic field that is perpendicular to their velocity. The radius of the resulting electron trajectory is:

Correct Answer
verified

The figure shows the motion of electrons in a wire which is near the N pole of a magnet. The wire will be pushed:

Correct Answer
verified

An electron moves in the negative x direction, through a uniform magnetic field in the negative y direction. The magnetic force on the electron is:

Correct Answer
verified

A loop of wire carrying a current of 2.0 A is in the shape of a right triangle with two equal sides, each 15 cm long. A 0.7 T uniform magnetic field is parallel to the hypotenuse. The resultant magnetic force on the two sides has a magnitude of:

Correct Answer
verified

An electron and a proton are both initially moving with the same speed and in the same direction at 90˚ to the same uniform magnetic field. They experience magnetic forces, which are initially:

Correct Answer
verified

You are facing a loop of wire which carries a clockwise current of 3.0 A and which surrounds an area of 5.8 10⁻²m². The magnetic dipole moment of the loop is:

Correct Answer
verified

A circular loop of wire with a radius of 20 cm lies in the xy plane and carries a current of 2 A, counterclockwise when viewed from a point on the positive z axis. Its magnetic dipole moment is:

Correct Answer
verified

A current is clockwise around the outside edge of this page and a uniform magnetic field is directed parallel to the page, from left to right. If the magnetic force is the only force acting on the page, the page will turn so the right edge:

Correct Answer
verified

The units of magnetic dipole moment are:

Correct Answer
verified

Correct Answer
verified

A uniform magnetic field is directed into the page. A charged particle, moving in the plane of the page, follows a clockwise spiral of decreasing radius as shown. A reasonable explanation is:

Correct Answer
verified

Exam 28: Magnetic Fields

An electron enters a region of uniform perpendicular fields. It is observed that the velocity of the electron is unaffected. A possible explanation is:

Correct AnswerverifiedShow Answer

An electron is moving north in a region where the magnetic field is south. The magnetic force exerted on the electron is:

Correct AnswerverifiedShow Answer

The diagrams show five possible orientations of a magnetic dipole in a uniform magnetic field For which of these does the magnetic torque on the dipole have the greatest magnitude?

Correct AnswerverifiedShow Answer

A hydrogen atom that has lost its electron is moving east in a region where the magnetic field is directed from south to north. It will be deflected:

Correct AnswerverifiedShow Answer

At any point the magnetic field lines are in the direction of:

Correct AnswerverifiedShow Answer

A loop of current-carrying wire has a magnetic dipole moment of 5 * 10-4 A . m2. The moment initially is aligned with a 0.5-T magnetic filed.To rotate the loop so its dipole momentt is perpendicular to the field and hold it in that orentation, you must do work of:

Correct AnswerverifiedShow Answer

An electron (charge = -1.6 * 10-19C) is moving at 3 * 105 m/s in the positive x direction. A magnetic field of 0.8 T is in the positive z direction. The magnetic force on the electron is:

Correct AnswerverifiedShow Answer

A magnetic field exerts a force on a charged particle:

Correct AnswerverifiedShow Answer

A charged particle is projected into a region of uniform, parallel, fields. The force on the particle is:

Correct AnswerverifiedShow Answer

Electrons (mass m, charge -e) are accelerated from rest through a potential difference V and are then deflected by a magnetic field that is perpendicular to their velocity. The radius of the resulting electron trajectory is:

Correct AnswerverifiedShow Answer

The figure shows the motion of electrons in a wire which is near the N pole of a magnet. The wire will be pushed:

Correct AnswerverifiedShow Answer

An electron moves in the negative x direction, through a uniform magnetic field in the negative y direction. The magnetic force on the electron is:

Correct AnswerverifiedShow Answer

A loop of wire carrying a current of 2.0 A is in the shape of a right triangle with two equal sides, each 15 cm long. A 0.7 T uniform magnetic field is parallel to the hypotenuse. The resultant magnetic force on the two sides has a magnitude of:

Correct AnswerverifiedShow Answer

An electron and a proton are both initially moving with the same speed and in the same direction at 90˚ to the same uniform magnetic field. They experience magnetic forces, which are initially:

Correct AnswerverifiedShow Answer

You are facing a loop of wire which carries a clockwise current of 3.0 A and which surrounds an area of 5.8 10−2m2. The magnetic dipole moment of the loop is:

Correct AnswerverifiedShow Answer

A circular loop of wire with a radius of 20 cm lies in the xy plane and carries a current of 2 A, counterclockwise when viewed from a point on the positive z axis. Its magnetic dipole moment is:

Correct AnswerverifiedShow Answer

A current is clockwise around the outside edge of this page and a uniform magnetic field is directed parallel to the page, from left to right. If the magnetic force is the only force acting on the page, the page will turn so the right edge:

Correct AnswerverifiedShow Answer

The units of magnetic dipole moment are:

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A uniform magnetic field is directed into the page. A charged particle, moving in the plane of the page, follows a clockwise spiral of decreasing radius as shown. A reasonable explanation is:

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

A loop of current-carrying wire has a magnetic dipole moment of 5 * 10^-⁴ A . m². The moment initially is aligned with a 0.5-T magnetic filed.To rotate the loop so its dipole momentt is perpendicular to the field and hold it in that orentation, you must do work of:

Correct Answer
verified

An electron (charge = -1.6 * 10^-¹⁹C) is moving at 3 * 10⁵ m/s in the positive x direction. A magnetic field of 0.8 T is in the positive z direction. The magnetic force on the electron is:

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

You are facing a loop of wire which carries a clockwise current of 3.0 A and which surrounds an area of 5.8 10⁻²m². The magnetic dipole moment of the loop is:

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified