Electrostatics Worksheet
Answer the questions below in clear and complete sentences.
1. A piece of PVC pipe is rubbed with a fleece cloth, causing the PVC pipe to become negatively
charged.
a. What type of charging is this?
b. Explain why the PVC pipe becomes negatively charged.
2. A glass rod is rubbed with a cotton cloth, causing the glass rod to become positively charged.
a. What type of charging is this?
b. Explain why the glass rod becomes positively charged.
3. During a physics demonstration, Elektra rubs a rubber balloon on her hair to create a static charge.
The charging causes the balloon to stick to her head.
a. Which object gains electrons? (See the slide on electronegativity in the notes.)
b. Which object loses electrons?
4. An electroscope is a device that is used to detect the
presence of electric charge on an object. When a
negatively charged rod is moved close to the metal plate
on the top of the electroscope, electrons on the plate are
repelled and move away from the rod. The metal plate
becomes positively charged. Refer to your notes to
answer the questions below.
a. What type of charging is this?
b. A person then touches the metal plate with their finger, giving them a shock. What type of
charging is this?
The elementary charge (abbreviated e or qe) is the electric charge of a single electron or a single
proton. The electron is said to have a negative charge while the proton has a positive charge. The
SI unit of electric charge is the Coulomb (C). The value of the elementary charge is:
qe = 1.60 x 10 -19 C
5. What is the total electric charge of 100 electrons? (Remember to include units!)
6. A glass rod is charged by rubbing it with a cotton cloth, giving the rod a net (total) positive charge
of +1.04 x 10-13 Coulombs.
a. Which object gained electrons?
b. Which object lost electrons?
c. How many electrons were transferred from the glass rod to the cloth?
7. A balloon that is initially neutral is rubbed with a wool cloth. A total of 85 x 108 electrons are
transferred from the wool to the balloon. What is the net (total) charge on the balloon?
8. A strong lightning bolt can transfer 25 Coulombs of charge. How many electrons would be
transferred by the lightning bolt to the ground?
9. The diagram to the right shows a rubber rod
charging a metal sphere.
a. What is the initial charge of the
sphere?
b. How many electrons are transferred
from the rod to the sphere?
c. What is the final charge of the sphere?
10. Two charges, separated by a distance of 4 cm, produce an attractive force of 12 Newtons between
them. The two charges are:
a. Both positive
b. Both negative
c. Oppositely charged (one is positive and one is negative)
d. More information is needed.
11. Two charges, separated by a distance of 4 cm, produce an attractive force of 12 Newtons. If the
distance between the charges is increased to 8 cm, what is the new force between them?
a. 3 N
b. 4 N
c. 6 N
d. 24 N
12. When the distance between two charges is halved, the electrical force between the charges:
a. quadruples
b. reduces to ¼
c. halves
d. doubles
13. Electrostatic force F is directly proportional to:
a. r2
b. q1
c. q2
d both q1 & q2
14. Two charges q1 & q2 experience an electrostatic force F when the distance between them is r. If the
q1 doubles and the q2 halves for the same distance, the force between them:
a. doubles
b. triples
c. halves
d. remains the same
15. Which of the following is not a good insulator?
a. copper
b. glass
c. rubber
d. wool
16. Which of the following is not a good conductor of electricity?
a. copper
b. silver
c. glass
d. aluminum