D. Magnetism (chapter 19) On-line Quiz

18 questions worth 16.666 points each

1.  Breaking a bar magnet in half will produce

    a. a single north magnetic monopole

    b. a single south magnetic monopole

    c. one north and one south monopole

    d. two bar magnets

2.  A vertical wire carries a current straight up in a region where the magnetic field vector points due north.  What is the direction of the resulting force on this current?

    a. Down

    b. North

    c. East

    d. West

3.  A charged particle is injected into a uniform magnetic field such that its velocity vector is perpendicular to the magnetic field vector.  Ignoring the particle's weight, the particle will

    a. move in a straight line.

    b. follow a spiral path.

    c. move along a parabolic path.

    d. follow a circular path.

4.  A charged particle is observed traveling in a circular path in a uniform magnetic field.  If the particle had been traveling twice as fast, the radius of the circular path would be

    a. twice the original radius.

    b. four times the original radius.

    c. one-half the original radius.

    d. one-fourth the original radius.

5.  The maximum torque is exerted on a current loop when the plane of the loop is at what angle to the magnetic field?

    a. 0.^o

    b. 45. ^o

    c. 90. ^o

    d. 135. ^o

6.  A particle carrying a charge of +1 e travels in a circular path in a uniform magnetic field.  If instead the particle carried a charge of +2 e, the radius of the circular path would have been

    a. twice the original radius.

    b. four times the original radius.

    c. one-half the original radius.

    d. one-fourth the original radius.

7.  The magnetic force between parallel wires is used by the National Bureau of Standards to define the:

    a. Tesla

    b. Newton

    c. square-meter

    d. Ampere

8.  At double the distance from a long current-carrying wire, the strength of the magnetic field produced by that wire decreases to

    a. 1/8 of its original value.

    b. 1/4 of its original value.

    c. 1/2 of its original value.

    d. none of the above.

9.  A horizontal wire carries a current straight toward you.  From your point of view, the magnetic field caused by this current

    a. points directly away from you.

    b. points to the left.

    c. circles the wire in a clockwise direction.

    d. circles the wire in a counter-clockwise direction.

10. A wire lying in the plane of the page carries a current toward the bottom of the page, as shown.  What is the direction of the magnetic force it produces on an electron that is moving perpendicularly toward the wire, also in the plane of the page, from your right?

    a. Zero

    b. Perpendicular to the page and towards you

    c. Perpendicular to the page and away from you

    d. Toward the top of the page

    e. Toward the bottom of the page

11. Parallel wires carrying currents in the same direction will:

    a. repel each other

    b. attract each other

    c. neither attract nor repel

    d. exert a torque on each other

12. When a ferromagnetic material is placed in an external magnetic field, the net magnetic field of its magnetic domain becomes

    a. zero

    b. smaller

    c. larger

13. Like magnetic poles repel or attract?

14. At a particular instant, an electron moves eastward in a uniform magnetic field that is directed straight downward.  The magnetic force that acts on it is

    a. zero.

    b. directed upward.

    c. directed to the south.

    d. none of the above.

15. A charged particle moves and experiences no magnetic force.  From this we can conclude that

    a. no magnetic field exists in that region of space.

    b. the particle is moving parallel to the magnetic field.

    c. the particle is moving at right angles to the magnetic field.

    d. either no magnetic field exists or the particle is moving parallel to the field.

16. A charged particle moving along a direction perpendicular to the plane of a loop of current-carrying wire, and which passes through the loop's center, will experience

    a. no magnetic force

    b. a magnetic force perpendicular to its velocity

    c. a magnetic force parallel to the loop axis

    d. a magnetic torque

17. Consider electrons flowing southward along a horizontal power line.  The magnetic field generated directly below the wire by the current is pointing:

    a. eastward

    b. westward

    c. northward

    d. southward

    e. up

    f. down

18. A charged particle moves with its velocity perpendicular to a magnetic field.  The field acts to change the particle's:

    a. mass

    b. charge

    c. velocity

    d. magnitude of momentum