Camas B Invitational
Shock Value
12/11/10
Multiple Choice
Circle the letter of the choice that best completes the statement or answers the question.
1. Where is the magnitude of the magnetic field around a permanent magnet greatest?
a. close to the poles
b. far from the poles
c. The magnitude is equal at all points on the field.
d. The magnitude depends on the material of the magnet.
2.Which compass needle orientation in the figure above might correctly describe the magnet’s field at that point?
c. c
a. a
b. b
d. d
3. Which describes magnetic declination?
a. the angle between Earth’s magnetic field and Earth’s surface
b. Earth’s magnetic field strength at the equator
c. the tendency for Earth’s field to reverse itself
d. the angle between directions to true north and magnetic
4. A current in a solenoid with N turns creates a magnetic field inside the solenoid. The magnetic field strength is
directly proportional to the
a. number of turns only.
b. strength of the current only.
c. number of turns in the loop and the strength of the current.
d. size of the solenoid.
5.In a permanent magnet,
a. domain alignment persists after the external magnetic field is removed.
b. domain alignment becomes random after the external magnetic field is removed.
c. domains are always randomly oriented.
d. the magnetic fields of the domains cancel each other.
6. In soft magnetic materials, what happens when an external magnetic field is removed?
a. The domain alignment persists.
b. The orientation of domains fluctuates.
c. The material becomes a hard magnetic material.
d. The orientation of domains changes, and the material returns to an unmagnetized
state.
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Camas B Invitational
7.Resistance is measured in a unit called the ____.
a. ampere
b. coulomb
Shock Value
c. ohm
d. volt
8.The statement that current is equal to the voltage difference divided by the resistance is known as ____.
a. Einstein's equation
c. Newton's law
b. Faraday's law
d. Ohm's law
9.A path that allows only one route for an electric current is called a ____.
a. parallel circuit
c. series circuit
b. parallel current
d. series current
10.A static discharge differs from an electric current in that a static discharge ____.
a. involves the movement of ions as well as electrons
b. is a flow of electrons
c. lasts for only a fraction of a second
d. results because a force is exerted on the electrons
11. Which of the following is a device designed to open an overloaded circuit and prevent overheating?
c. resistor
a. circuit breaker
b. magnet
d. transformer
12. The function of an electric motor is to change ____.
a. chemical energy to electrical energy
b. electrical energy to chemical energy
c. electrical energy to mechanical energy
d. mechanical energy to electrical energy
13.A dry-cell battery produces ____.
a. an alternating current
b. a direct current
c. the same current that a generator produces
d. both direct and alternating current
14. The magnetic force of a magnet is ____.
a. the same at all parts of the magnet
b. strongest at the center
c. strongest at the poles
d. weakest at the poles
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12/11/10
Camas B Invitational
Shock Value
12/11/10
Short Answer
15. A bar magnet is suspended and allowed to rotate freely. If the magnetic field of Earth is considered to be
equivalent to that of a large bar magnet, which pole of the suspended magnet would point toward the magnetic
north pole of Earth?
South Pole
16. (2 points) If the head of an iron nail touches a magnet, the nail will become a magnet by induction. If the nail
touches the north pole of the magnet, what kind of pole is at the point of the nail? Explain.
The end of the magnetized nail touching the north pole of the magnet will be a south pole by induction.
Otherwise, it would be repelled by the magnet. The tip of the nail that points away from the magnet must
have the opposite polarity and thus will be a north pole.
17. (2 points) How can the magnetic field around a permanent magnet be determined?
It can be determined with a compass. The direction of the magnetic field is defined as the direction in
which the north pole of a compass needle points at that location.
18. The magnetic field of a bar magnet is shown in the figure above. Is the magnet’s north pole at A or B?
A
19. Which magnetic pole is at the geographic North Pole of Earth?
The magnetic south pole is located at the geographic North Pole of Earth.
20. Will the magnets in the figure above attract or repel each other?
Attract
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Camas B Invitational
Shock Value
12/11/10
21. (2 points) Which bulbs will have a current in the schematic diagram above?
22. In the schematic diagram above, will there be a current?
23. Will the magnets in the figure above attract or repel each other?
The First
Yes
Repel
24. (2 points) Describe how you could quickly determine whether a string of lights is wired in series or in parallel.
Remove one bulb. If it's a series, all the lights will go out; if it's parallel, the remaining lights will stay lit.
25. (2 points) List two materials that are conductors and two materials that are insulators.
metals, copper, silver, gold, salt water;
insulators: plastic, wood, rubber, glass, vacuum
26. (2 points) Explain how an electromagnet works.
When a current flows through a coil of wire, magnetic field lines form around the coil. The more loops of
wire, the stronger the magnetic field.
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Camas B Invitational
Shock Value
12/11/10
Station 1 (20 points)
Record Data Table here:
Battery Clip
V0 (volts)
V (volts)
I (mA)
4 AA
5.74
5.27
320
2 AA
3.12
2.83
230
Note: Actual values may vary with batteries used on the day of test by +/- 10%
R (Ω)
16.5
12.3
5 points for table set up, must label units used
3 points for each value of R calculated correctly - 6 total (R = V/I)
1 point for each value of V and I measured - 6 total
The resistances are different in the two cases (3 points)
BONUS (5 points) if they identify that the resistance of the light bulb increases as more current goes
through it and the filament heats up.
Station 2 (10 points)
Draw the electronic symbols: (2 points each)
a)
b)
c)
+
-
d)
e)
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Camas B Invitational
Shock Value
Station 3 (10 points)
Good Batteries:1, 3, 4, 7, 9, 10
Bad Batteries: 2, 5, 6, 8
Station 4 (15 points)
a) (5 points) Describe in words:
A in series with B in series with C and D in parallel
b) (2 points) Lights on: None
c) (5 points) Draw the circuit:
d) (3 points) Lights on: B and C and D
BONUS (2 points) if they describe B is brighter than C & D (which are the same)
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12/11/10
Camas B Invitational
Shock Value
12/11/10
Station 5 (10 points)
Using the compasses provided map out where the magnets are and indicate N/S poles. (Yes you can
lay this sheet on the board!)
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