Question

A charged balloon is placed near the wall. This attracts the protons in the wall while
repelling the walls electrons. This is an example of ...
a. conduction b. conductor c. induction d. Friction
13. A person walks across the carpet, rubbing their feet. Next, they touch the doorknob,
transferring electrons into the doorknob. Which statement demonstrates conduction?
a. Walking across the carpet
b. Touching the doorknob
c. No conduction was demonstrated.
14. An electrically charged metal rod touches a neutral metal ball. Which statement best
describes what will happen next.
a. The protons within the rod will be transferred into the metal ball and spread out evenly across
the metal ball.
b. The electrons within the rod will be transferred into the metal ball and stay in a central
location.
c. The protons within the rod will be transferred into the metal ball and stay in the central
location.
d. The electrons within the rod will be transferred into the metal ball and spread out evenly.

Answer 1

12. c. induction
- The balloon causes a redistribution (polarization/induction) of charge in the wall without direct contact.

13. b. Touching the doorknob
- Conduction is transfer of charge by direct contact; the touch transfers electrons from the person to the knob. Walking on the carpet is charging by friction.

14. d. The electrons within the rod will be transferred into the metal ball and spread out evenly.
- In metals, electrons are mobile and will move on contact until charge is shared and distributes over the conductor’s surface; protons are fixed in the atomic nuclei and do not move.