7th Grade Science Electricity and Magnetism Test Review

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7th Grade Science
Electricity and Magnetism
Test Review
1. Consider the two objects below.
What will happen if the two objects get close to one another?
A. *They will be attracted to each other
B. They will be repelled by each other.
C. Nothing will happen.
D. They will spin around each other.
2.
3.
a.
b.
c.
d.
Two balloons have strings tied to them. The balloons have like charges. What will most likely happen when
the balloons are held near each other?
They will accelerate toward each other.
*They will accelerate away from each other.
They will spin counterclockwise.
They will spin clockwise.
4. Consider the diagram below.
Which of the following best explains why the stream of water bends when the balloon is brought near it?
A. *There is an electrical attraction between the water molecules and the balloon.
B. There is gravitational attraction between the water molecules and the balloon.
C. There is nuclear repulsion between the water molecules and the balloon.
D. There is magnetic repulsion between the water molecules and the balloon.
7th Grade Science
Electricity and Magnetism
Test Review
5. What happens to the force of attraction or repulsion between two objects as the distance between them
increases?
A. The force increases.
B. *The force decreases.
C. The force stays the same.
D. There is no force between them.
6. Which graph best represents the relationship discussed in number 5?
A.*
B.
C.
D. None of these choices are correct.
7. The diagram below shows the electric field lines around two negatively charged objects.
According to the electric field lines, how will these two objects move?
A. They will move away from each other in the same direction because one is larger than the other.
B. They will move toward each other because the charges are the same.
C. *They will move away from each other and in opposite directions because like charges repel.
D. They will move toward each other because like charges attract.
8. Consider the electric circuit in the picture below.
Which statement below identifies the type of circuit in this picture correctly and explains why?
A. series circuit, because it has two bulbs
B. parallel circuit, because the same amount of current is flowing through both bulbs
C. *series circuit, because the current is divided between the two bulbs
D. parallel circuit, because it has only one battery
7th Grade Science
Electricity and Magnetism
9. In the circuit below, which bulb(s) would be lit?
A.
B.
C.
D.
*the one on top only
the one on bottom only
both bulbs would be lit
neither bulb would be lit
10. Consider the circuit in the diagram below.
What will happen if bulb A burns out?
A. Bulbs B and C will also go out.
B. *Bulbs B and C will stay lit and become brighter.
C. Bulb B and C will become less bright.
D. Bulbs B and C will flash off and on.
11. Which statement describes a parallel circuit?
A. There is only one path for electricity to take.
B. *There is more than one path for electricity to take.
C. The flow of electricity comes from more than one source.
D. If one bulb goes out, the rest will also go out.
12. In which circuit below will the bulb(s) shine brightest? *Circuit B
Circuit C
Circuit D
Test Review
7th Grade Science
Electricity and Magnetism
Test Review
13. If you wanted to replace wire A in the circuit below with a different wire, which material could be used so that the
lights would still come on?
A.
B.
C.
D.
*an iron nail
a piece of cotton string
a plastic ruler
a wooden stick
14. What materials make the best conductors and could be used as part of a circuit?
A. cotton balls
B. notebook paper
C. *metal objects
D. toothpicks
15. Consider the bar magnets in the diagram below.
What would happen to the force between the two magnets if they were placed closer together?
A. The force would be weaker.
B. *The force would be stronger.
C. The force would remain the same.
D. The force would cause the magnets to repel.
16. What would the two bar magnets in number 15 do if they were placed closer together?
A. spin around
B. push away from each other
C. *push toward each other
D. break into pieces
17. Consider the magnetic field lines in the diagram below.
Where is the magnetic field in this diagram the strongest?
A. *Between the two magnets
B. On the left side
C. On the right side
D. At the top and bottom
7th Grade Science
Electricity and Magnetism
Test Review
18. The diagram below shows the magnetic field lines of Earth. Where is Earth’s magnetic field the strongest?
A.
B.
C.
D.
*At the poles
In the East
In the West
It is impossible to tell.
19. Correctly draw the magnetic field lines around the magnet below. Magnetic field lines run from north to south and
never cross or touch.
20.
7th Grade Science
Electricity and Magnetism
21.
22.
23. Consider the diagram below.
This is a diagram of a(n)
A. *Electromagnet
B. Magnet
C. Electric circuit
D. Light source
24. Which of these would be a use for an electromagnet?
A. a compass
B. a flash light
C. a radio
D. *a crane at a scrap yard
25.
Test Review
7th Grade Science
Electricity and Magnetism
Test Review
26. An electromagnet converts ________________ into magnetic energy.
A. heat energy
B. Chemical energy
C. *Electrical energy
D. Solar energy
27. Which data table most accurately indicates how the number of turns of wire affects the strength of an
electromagnet?
A. *
C.
Number of
Paper Clips
Turns of
picked up
Number of
Paper Clips
wire
Turns of
picked up
wire
10
3
10
3
20
6
20
3
30
15
30
3
40
25
40
3
B.
D.
Number of
Paper Clips
Turns of
picked up
Number of
Paper Clips
wire
Turns of
picked up
wire
10
25
10
0
20
15
20
0
30
6
30
0
40
3
40
0
28.
29. Electrons and protons have __________________.
A. electric fields
B. electric rays
C. *electric charges
D. electrolysis
30. Which term is described most accurately by this definition: A field around charged particles that exerts a force
on other charges particles.
A. Magnetic field
B. *Electric field
C. Force field
D. Laser field
7th Grade Science
Electricity and Magnetism
Test Review
31. Which data table matches the graph below that shows the relationship between magnetism and electric current?
A.
Current(Amps)
5
Number of
paper clips
20
10
15
20
B.
Current(Amps)
5
Number of
paper clips
20
20
20
10
15
40
60
20
20
80
5
Number of
paper clips
80
10
15
20
32.
C. *
Current(Amps)
D.
Current(Amps)
5
Number of
paper clips
80
60
40
10
15
75
70
20
20
65
7th Grade Science
Electricity and Magnetism
Test Review
33. In the picture below, circle the circuits in which the light would light up. The first, fourth, and fifth circuits would
have bulbs that light up because the circuits have no breaks and both sides of the battery and/or light are connected to the rest
of the circuit.
34. Which are the correct materials to use to build an electromagnet?
A. An iron nail, some wire, and a magnet
B. An iron nail, some string, and a battery
C. *An iron nail, some wire, and a battery
D. A toothpick, some string, and a magnet
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