A. Static Electricity Quiz (Chapter 15)

On-Line Quiz

300 Points Possible (10 points each question)

 

1.  A neutral atom always has

    a. more neutrons than protons.

    b. more protons than electrons.

    c. the same number of neutrons as protons.

    d. the same number of protons as electrons.

 

2.  A glass rod is rubbed with a piece of silk.  During the process the glass rod acquires a positive charge and the silk

    a. acquires a positive charge also.

    b. acquires a negative charge.

    c. remains neutral.

    d. could either be positively charged or negatively charged.  It depends on how hard the rod was rubbed.

 

3.  An electron and a proton are separated by a distance of 1 m.  What happens to the size of the force on the proton if the electron is moved 0.5 m closer to the proton?

    a. It increases to 4 times its original value.

    b. It increases to 2 times its original value.

    c. It decreases to one-half its original value.

    d. It decreases to one-fourth its original value.

 

4.  Two charges are separated by 5.0 meters and attract one another.  If one charge is halved, the other tripled, and the distance quartered, by what factor does the attraction change?

    a. 2

    b. 3

    c. 16

    d. 24

    e. 48

 

5.  An electron, free to move when placed in an electric field, moves

    a. along the field line, opposite the field

    b. along the field line, in the field direction

    c. perpendicular to the field line

    d. unaffected by the field

 

6.  Sphere A carries a net charge and sphere B is neutral.  They are placed near each other on an insulated table.  Which statement best describes the electrostatic force between them?

    a. There is no force between them since one is neutral.

    b. There is a force of repulsion between them.

    c. There is a force of attraction between them.

    d. The force is attractive if A is charged positively and repulsive if A is charged negatively.

 

7.  An electric dipole placed into a uniform electric field feels a net force:

    a. along the field

    b. opposite the field

    c. perpendicular to the field

    d. of zero magnitude

 

 

8.  A point charge of +Q is placed at the center of a square, and a second point charge of -Q is placed at the upper-left corner.  It is observed that an electrostatic force of 2 N acts on the positive charge at the center.  What is the magnitude of the force that acts on the center charge if a third charge of -Q is placed at the lower-left corner?

    a.     Zero

    b.      2 N

    c.     4 N

    d.     None of the above

 

9.  An electric dipole placed into a non-uniform electric field feels a net force:

    a. parallel to the field

    b. perpendicular to the field

    c. of zero magnitude

 


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10. A point charge of +Q is placed at the centroid of an equilateral triangle.  When a second charge of +Q is placed at one of the triangle's vertices, an electrostatic force of 4 N acts on it.  What is the magnitude of the force that acts on the center charge when a third charge of +Q is placed at one of the other vertices?

    a. Zero

    b. 4 N

    c. 8 N

    d. None of the above

 

11. Which of the following makes an approximate uniform electric field?

    a. a very long line of positive charge

    b. very large, closely separated, parallel oppositely charged plates

    c. two long parallel, closely separated, oppositely charged lines of charge

    d. a metal charged cylinder

 

12. The electric field at the surface of a conductor is

    a. parallel to the surface

    b. perpendicular to the surface

    c. always zero

    d. never zero

 

13. Electric field lines

    a. are closer together the stronger the field

    b. start on negative charges and end on positive charges

    c. were invented by Isaac Newton

    d. are perpendicular to the lines of force.

 

14. Electric field lines

    a. circle clockwise around positive charges.

    b. circle counter-clockwise around positive charges.

    c. radiate outward from negative charges.

    d. radiate outward from positive charges.

 


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15. Two stationary point charges q1 and q2 are shown in the sketch along with some electric field lines representing the field between them.  What can you deduce from the sketch?

    a. q1 and q2 have the same sign; the magnitudes are equal.

    b. q1 and q2 have the same sign; the magnitude of q1 is greater than the magnitude of q2.

    c. q1 is positive and q2 is negative; the magnitude of q1 is greater than the magnitude of q2.

    d. q1 is negative and q2 is positive; the magnitudes are equal.

 

 

16. The electric field shown

    a. increases to the right.

    b. increases down.

    c. decreases to the right.

    d. decreases down.

    e. is uniform.

 

17. A force of 6 N acts on a charge of 3mC when it is placed in a uniform electric field.  What is the magnitude of this electric field?

    a. 18 m N/C

    b. 2 m N/C

    c. 0.5 m N/C

    d. None of the above

 


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18. If a solid metal sphere and a hollow metal sphere of equal diameters are each given the same charge, the electric field (E) midway between the sphere center and the surface is

    a. greater for the solid sphere than for the hollow sphere.

    b. greater for the hollow sphere than for the solid sphere.

    c. zero for both.

    d. equal in magnitude for both, but one is opposite in direction from the other.

 

19. A hollow metallic sphere is placed in a region permeated by a uniform electric field that is directed upward.  Which statement is correct concerning the electric field in the sphere's interior?

    a. The field is zero everywhere in the interior.

    b. The field is directed upward.

    c. The field is directed downward.

    d. The field is zero only at the sphere's exact center.

 

20. A positive charge is enclosed in a hollow metallic sphere that is not grounded.  At a point directly above the hollow sphere, the electric field caused by the enclosed positive charge has

    a. diminished to zero.

    b. diminished somewhat.

    c. increased somewhat.

    d. not changed.

 

21. A positive point charge is enclosed in a hollow metallic sphere that is grounded.  At a point directly above the hollow sphere, the electric field caused by the enclosed positive charge has

    a. diminished to zero.

    b. diminished somewhat.

    c. increased somewhat.

    d. not changed.

 

22. Which of the following is a vector?

    a. Electric constant k

    b. Electric charge

    c. Electric field

    d. All of the above

 

23. Several electrons are placed on a hollow metal sphere.  They

    a. clump together on the sphere's outer surface.

    b. clump together on the sphere's inner surface.

    c. become uniformly distributed on the sphere's outer surface.

    d. become uniformly distributed on the sphere's inner surface.

 

24. Electric Dipoles always consist of two charges that are

    a. equal in magnitude; opposite in sign.

    b. equal in magnitude; both are negative.

    c. equal in magnitude; both are positive.

    d. unequal in magnitude; opposite in sign.

 

25. In electricity, what quantity is analogous to the "acceleration of gravity" g (which is a force per unit mass):  

    a. electric force

    b. electric field

    c. electric potential

    d. electric charge

 

26. The force which binds, or holds, atoms together to form molecules is

    a. magnetic

    b. electrical

    c. gravitational

    d. nuclear

    e. friction

 

27. When an electron is removed from a neutral atom, it becomes:

    a. a positive ion

    b. a negative ion

    c. a bipolar atom

    d. heavier

    e. none of the above

 

28. The electric constant (k in kqQ/r2) is

    a. negative for negative charge

    b. positive for all charges

    c. equals 1 in SI units

    d. positive only for positive charge

 

29. Which is true?

    a. unlike charges repel

    b. like charges attract

    c. all charges attract

    d. unlikes attract

 

30. Avogadro's number of protons is contained in a

    a. nucleus

    b. mole

    c. neutral atom