Download Electricity and Magnetism

Electricity and Magnetism
Review
Match the definition in column II with its meaning when used in a circuit diagram in column I by
writing the letter of the correct symbol in the blank on the left.
Column I
Column II
________ 1. negative
a.
rate at which electrical energy is changed to another
energy form
________ 2. friction
b. unit of electrical energy
________ 3. insulator
c. charge on an electron
________ 4. voltage
d. charge on a proton
________ 5. resistance
e.
process of transferring charge by rubbing of contact
________ 6. circuit breaker
f.
rearrangement of electrons on a neutral object caused
by a nearby charged object
g.
circuit with only one path
________ 7. Power
________ 8. kilowatt-hour
h. circuit with more than one path
________ 9. current
i. doesn’t allow electrons to move through it easily
________ 10. parallel circuit
j. tendency of a material to oppose the flow of electrons
k. flow of electrons through a conductor
L. related to the force that causes electric charges to flow
M. piece of metal that bends when large current flows
For the following short answer questions show all work, including equations, and write in complete
sentences.
11. a) Someone pulls off their sweater and becomes negatively charged? What unbalanced charge
remains on the sweater? Why would your hair cling to the sweater as it is pulled over your head?
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b) The person opens a door but gets a shock just before they touch it. Explain why using the following
picture.
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c) What does the following devise detect? If the person above had put their hand over the top (not
touching) after pulling off their sweater, what would happen? Explain!
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12. Describe Ohm’s Law:
13.
Determine the a) current flowing and b) power dissipated by the bulb in the circuit below.
Work:
c) If the light was left on for the weekend (2 days) how much would it cost the owner if the electrical
utility company charges $0.10 per kW-hr
Work:
14.
The bulbs and batteries in the two circuits shown below are identical.
B
Y
A
X
Circuit 1
Circuit 2
a) Which circuit above describes the most closely the way your home is wired? Explain your answer!
Circuit _____ because _________________________________________________________________
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b) If a wire was attached between points A and B in circuit 2, would this change effect the brightness of
each individual bulb in the circuit? If yes, explain in what way each bulb would be effected. Identify the
two bulbs as X and Y (as shown).
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c) Each light bulb in circuit 1 has a resistance of 8. The potential difference across the ends of the
battery is 16V. Determine the current coming in and out of the battery.
Work:
Itotal = ___________
d) Determine i) the total resistance to the flow of charge and ii) the power dissipated in the circuit.
Work:
R total = ____________
Ptotal = ____________
15. What is the cause of all magnetism?
16.
N
a) Draw the magnetic field around the bar magnet and the current carrying wire shown below.
S
I
b) Show on the two diagrams above which way a compass needle would point above and below each
object.
17. What happens if a wire is moved through a magnetic field (perpendicular to the field lines)?
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18. Explain the operation of the electric generator (used in power stations). How does the operation of an
electric motor differ from an electric generator?
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