Download Electrical Potential Review

Electrical Potential Review
V=J/C
E = V /M and E = N / C
1. Electric potential is defined as the amount of _____ energy per charge.
2. When work is done on a positive test charge by an external force to move it from one location to
another, electric potential _________ (increases, decreases) and potential energy _________
(increases, decreases)
3. When NO work is done on a positive test charge by an external force to move it from one location
to another, electric potential _________ (increases, decreases) and potential energy _________
(increases, decreases)
4. (True / False) Moving an electron within an electric field would change the amount of charge on the
electron. Explain
5. What does the battery supply to an electrical circuit?
a. protons
b. charges (electrons)
c. energy (potential difference)
6. A battery with a high voltage can do more ____ on each charge than a battery with a low voltage
7. Scientists use gel electrophoresis to separate fragments of DNA from a suspect. What would be
the advantage of using high voltage over low voltage for the electrophoresis?
8. The diagram below at the right shows a light bulb connected by wires to the + and terminals of a car battery. Use the diagram in answering the next four questions.
a. At what point(s) is the electrical potential energy highest?
b. At what point(s) is the electrical potential energy highest?
c. Moving a positive charge from A to D requires work to be done (true / false)
d. Moving a positive charge from D to A requires work to be done (true / false)
9. The energy required to move +4 C of charge between points D and A is ____ J.
10. The following circuit consists of a D-cell and a light bulb. Is the voltage at C (< = >) the voltage at
D?
11. Use your understanding of the mathematical relationship between work, potential energy, charge
and electric potential difference to complete the following statements:
a. A 6-volt battery will increase the potential energy of 1 coulomb of charge by ____ joules.
b. A 6-volt battery will increase the potential energy of 2 coulombs of charge by ____ joules.
c. A 12-volt battery will increase the potential energy of ____ coulombs of charge by 6 joules.
W = -qV
D
A
C
B
+100V
+50V
E
0V
-50V
-100V
12. In a region of space, the electric potential is described by the set of equipotential lines shown
above. A –35.0 μC charge will be moved from one location to another in this region.
a. On the diagram, indicate the Electric Field direction at the points: A, B, C, D and E.
b. Between which two points is there the greatest potential difference?
c. Between which two locations will the work done by the Electric Field on the charge be the
greatest?
d. How much work is done by the Electric Field on the charge if it moves from point B to point
C?
e. How much work is done by the Electric Field on the charge if it moves from point E to point
D
f. Compare the magnitude of the work done on the charge when it moves from point A to
point B; when it moves from point A to point E; and from point E to point B.