Download HOME 3 REVIEW WORKSHEET Answer these questions on loose

HOME 3 REVIEW WORKSHEET
Answer these questions on loose leaf paper.
1. Sketch a vertical wire with current moving up (label the direction of the current). Draw the direction of the
magnetic field around the wire using the left hand rule.
2. Repeat the above for:
(a) a vertical wire with the current moving down,
(b) a horizontal wire with current moving to the right,
(c) a horizontal wire with current moving to the left.
3. Draw the shape of the magnetic field around a bar magnet. Show the direction of the field. Hint: Think about
how a compass would point in different locations around the bar magnet.
4. Where is the magnetic field of a bar magnet the strongest?
5. Why is wire coiled in order to make an electromagnet?
6. Where is the magnetic field of an electromagnet the strongest?
7. In what ways is an electromagnet similar to a bar magnet? In what ways is it different?
8. Give two ways to change the polarity (that is, reverse the North and South poles) of an electromagnet.
9. Give three ways to increase the strength of an electromagnet.
10. What does a galvanometer detect? How does magnetism play a role in the operation of a galvanometer?
11. How does a galvanometer show the amount of current? How does a galvanometer show the direction of
current?
12. The north side of a bar magnet is inserted into a solenoid connected to a galvanometer. The needle on the
galvanometer moves to the right. Describe what
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S
would happen to the galvanometer needle under
each of these conditions:
(a) The bar magnet remains at rest inside the
solenoid.
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S
(b) The bar magnet is pulled out of the solenoid.
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(c) The north side of the bar magnet is again
inserted into the solenoid, this time with a faster
speed.
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(d) The south side of the bar magnet is inserted
into the solenoid.
(e) The north side of the bar magnet is inserted into
the other end of the solenoid.
(f) The wires are connected to the galvanometer
are switched and the bar magnet is inserted in the
same way as at the beginning.
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S
N
N
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switched
13. If a vertical wire with a strong current passed through the ceiling and floor of our classroom, and we walked
“north” using a compass, what path would we follow?
14. How is an electric motor like a galvanometer? How is a generator like a bar magnet and solenoid?
15. Try to explain how an electric motor works, using the idea that a current in a wire creates a magnetic field.
16. Try to explain how a generator works, using the idea that a moving magnet can create an electric current in a
wire.
17. Can you tell, by watching the response of a galvanometer connected to a solenoid, what is moving – the bar
magnet, the solenoid, or both? Explain.
18. For the electric motor you built, show the energy conversions in a diagram, or explain them in words.
19. In the drawing below, can you tell whether there is a current in the solenoid? Explain.
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compass
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solenoid
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