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Concept Review: Electrostatics Ch. 14
Name _____________________
Period
______
Chapter 14: Electrostatics
1. Which force- gravitational or electrical-repels as well as attracts?
2. Gravitational forces depend on the property called mass. What comparable property underlines
electrical forces?
3. How do protons and electrons differ in their electric charge?
4. Is an electron in a hydrogen atom the same as an electron in a uranium atom?
5. Which has more mass- a proton or an electron?
6. In a normal atom, how many electrons are there compared with protons?
7. a. How do like charges behave?
b. How do unlike charges behave?
8. a. If electrons are rubbed from cat’s fur onto a rubber rod, does the rod become positively or
negatively charged?
b. How about the cat’s fur?
9.
What does it mean to say that charge is conserved?
10. a. How is Coulomb’s law similar to Newton’s law of gravitation?
b. How are the two laws different?
11. The SI unit of mass is the kilogram, what is the SI unit of charge?
12. The proportionality constant K in Coulomb’s law is huge in ordinary units, whereas the
proportionality constant G in Newton’s law of gravitation is tiny, what does this mean in terms
of the relative strengths of their two forces?
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13. Why does the weaker force of gravity dominate over electrical forces for astronomical objects?
14. a. Why are metals good conductors?
b. Why are materials such as rubber and glass good insulators?
15. a. What are the three main methods of charging objects?
b. Which method involves no touching?
16. What is lightning? What is the function of a lightning rod?
17. a. What are electric field lines?
b. How do their directions compare with the direction of the force that acts on a positive test
charge in the same region?
18. Why does your hair stand out when you are charged by a device such as a Van de Graaff
generator?
20. What is the relationship between the amount of work you do on an abject and its potential
energy?
21. How can the electrical potential energy of a charged particle in an electric field be increased?
22. What will happen to the electrical potential energy of a charged particle in an electric field
when the particle is released and free to move?
23. Clearly distinguish between electrical potential energy and electric potential.
24. If you do work to move a charge a certain distance against an electric field, and increase the
electrical potential energy as a result, what happens to the electric potential?
25. The SI unit for electrical potential energy is the Joule. What is the SI unit for electric potential?
26. How can electric potential be high when electrical potential energy is relatively low?
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27. You are not harmed by contact with a charged balloon, even though its voltage is very high. Is
the reason for this similar to why you are not harmed by the greater-than-1000 C sparks from a
Fourth of July-type sparkler?
28 a. If you do 12 J of work to push 0.001 C of charge from point A to point B in an electric field,
what is the voltage difference between points A and B?
b. When the charge is released, what will be its kinetic energy as it flies back past its starting
point A? What principle guides your answer?
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