Physics 222 Worksheet: Chapter 16, Electric Force

1) An atom consists of 19 protons, 20 neutrons, and 18 electrons. This is a:

a) neutral atom.

b) singly charged positive ion.

c) singly charged negative ion

d) doubly charged positive ion.

e) doubly charged negative ion.

2) Metals are

a) conductors.

b) insulators.

c) semiconductors.

3) Which of these contain the fewest free electrons?

a) conductors.

b) insulators.

c) semiconductors.

4) If the distance between two charges is doubled, the electrical force between them will be

a) doubled.

b) cut in half.

c) multiplied by four.

d) divided by four.

5) Q₁ is a positive charge and Q₂ negative. When placed near each other

a) Q₁ will attract Q₂ and Q₂ will repel Q₁ .

b) Q₁ will repel Q₂ and Q₂ will attract Q₁ .

c) Each charge attracts the other.

d) Each charge repels the other.

6) Q₁ = +10 mC and Q₂ = +20 mC.

a) The force on Q₁ is greater than the force on Q₂.

b) The force on Q₁ is less than the force on Q₂.

c) The force on each charge is the same.

7) When a positive rod is brought near an electroscope the leaves separate. This is because

a) one leaf becomes positive and the other negative.

b) both leaves become positive.

c) both leaves become negative.

8) Q₁ and Q₂ are two charges separated by distance d. If Q₁ and Q₂ are doubled the force will be

a) doubled.

b) cut in half.

c) multiplied by four.

d) divided by four.

Q1, Q2 and Qx are equal positive charges located as shown below.

9)

a) The resultant force on Qx is directed to the right.

b) The resultant force on Qx is directed to the left.

c) The resultant force on Qx is zero.

Ans: 1-b, 2-a, 3-b, 4-d, 5-c, 6-c, 7-c, 8-c, 9-a

Physics 222 Worksheet: Chapter 16, Electric Fields

1) The electric force acting on a test charge at a point divided by the value of the charge is the:

a) acceleration of the charge.

b) electric field created by the test charge.

c) electric field acting on the test charge.

d) the energy of the test charge.

2) The electric field at a distance of 2 mm from a test charge is ___ the field at a distance of 4 mm.

a) the same as

b) twice as strong as

c) four times as strong as

d) half as strong as

e) one fourth as strong as

3) The electric field midway between two equal positive charges

a) is twice as strong as the field of one charge alone.

b) is half as strong as the field of one charge alone.

c) is zero

4) The electric field midway between equal positive and negative charges

a) is twice as strong as the field of one charge alone and points toward the negative charge.

b) is twice as strong as the field of one charge alone and points toward the positive charge.

c) is zero

5) Which of the following is not true about electric field lines?

a) Lines begin on positive charge and end on negative.

b) Lines are close together where the field is strong.

c) The direction of the electric force on a charge is tangent to the field line.

d) All these statements are true.

e) None of these statements are true.

6) The electric field inside a positively charged conductor

a) is zero.

b) points outward.

c) points inward.

7) If a negative charge is moving to the north in an electric field which is directed to the north, the charge will:

a) speed up

b) slow down         

c) be unaffected

8) In the figure below Q1 is negative and Q2 is positive. The direction of the resultant field at the point shown is approximately:

a) a

b) b

c) c

d) d

e) e

f) f

g) g

h) h

Ans: 1-c, 2-e, 3-c, 4-a, 5-d, 6-a, 7-b, 8-h