4 minute read
Quiz
by AudioLearn
QUIZ
1. In identifying a volt as a change in electrical potential energy, what are its units?
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a. Joules b. Joule-coulombs c. Coulombs d. Joules per coulomb
Answer: d. The units of the volt are in joules per coulomb; these represent the change in potential energy as it relates to the charge of an electrical object.
2. In electricity, what is the best description of the voltage of something?
a. A measure of a system’s potential energy b. A measure of its difference in potential energy between two points c. A measure of the potential energy and kinetic energy of the system d. A measure of the potential energy minus the kinetic energy of the system
Answer: b. This is a measure of the difference in potential energy between two points with one point given an arbitrary zero voltage point.
3. What is the relationship between the electric potential of a point charge and the distance from the charge?
a. The electric potential is proportional to the distance from the point charge. b. The electric potential is proportional to the square of the distance from the point charge. c. The electric potential is inversely proportional to the distance from the point charge. d. The electric potential is inversely proportional to the square of the distance from the point charge.
Answer: c. The electric potential is inversely proportional to the distance from the point charge. This will lead to zero electric potential as the distance approaches infinity.
4. What is not true of equipotent lines around a point charge?
a. The potential will be greater near the point charge. b. No work is required to send a charge anywhere along an equipotent line. c. Work is required to send a charge between equipotent lines. d. An equipotent line will be parallel to the electric field lines.
Answer: d. The equipotent line is a line that has the same potential from a point charge. No work is necessary to send a charge anywhere along an equipotent line. Work is, however, required to send a charge between equipotent lines. These equipotent lines will be perpendicular to the electric field lines.
5. What is a capacitor in electricity?
a. It is a device that is grounded to zero. b. It is an insulated conductor. c. It is the same thing as a battery. d. It is a device that will store charge.
Answer: d. A capacitor is a device that will store charge by accepting charge that is separated between two plates.
6. What determines the amount of charge that a capacitor can hold?
a. The voltage applied and the size of the capacitor b. The distance between the two plates c. The insulation between the two plates d. The presence of repelling plates
Answer: a. The voltage applied to a capacitor and the size of the capacitor are directly related to the amount of charge that a capacitor can hold.
7. What is not true of a dielectric in a capacitor?
a. It will allow for an increased diameter between the two charge-separating plates. b. It is an insulator that can be used between the two charge-separating plates. c. It leads to a dielectric constant instead of a permittivity of free space in determining the capacitance. d. It increases the capacitance of a capacitor.
Answer: a. A dielectric is an insulator that can be used between the two charge-separating plates that can increase the capacitor’s capacitance. It will allow for a decreased diameter between the plates.
8. What is the relationship between the dielectric constant and the dielectric strength?
a. These are essentially the same thing in different units. b. The dielectric constant is based on that of a vacuum, while the dielectric strength depends on experimental evidence. c. These two values are multiples of each other. d. These two values are inversely proportional to one another.
Answer: b. The dielectric constant is arbitrary and is set with a vacuum being 1. The dielectric constant is the amount of voltage that can be applied before the substance begins to break down.
9. What happens to the capacitance of four capacitors connected in series?
a. The capacitance will be the average of the four capacitors. b. The capacitance will be less than that of a single capacitor alone. c. The capacitance will be the capacitance of each of the capacitors multiplied by one another. d. The capacitance will be the capacitance of each capacitor added together.
Answer: b. Because the inverse of the capacitances added together will be the inverse of the capacitance total, the total capacitance will be less
than the capacitance of one of the capacitors alone. It effectively creates a capacitor that has a very wide distance between the plates, which makes a less effective capacitor.
10. What happens to the capacitance of four capacitors connected in parallel?
a. The capacitance will be the average of the four capacitors. b. The capacitance will be less than that of a single capacitor alone. c. The capacitance will be the capacitance of each of the capacitors multiplied by one another. d. The capacitance will be the capacitance of each capacitor added together.
Answer: d. When capacitors are aligned in parallel, the capacitances of each capacitor are added together to make the total capacitance of the system.
