7Th Grade Scienceelectricity and Magnetismtest Review

7th Grade ScienceElectricity and MagnetismTest Review

1. Consider the two objects below.

What will happen if the two objects get close to one another?

1. *They will be attracted to each other
2. They will be repelled by each other.
3. Nothing will happen.
4. They will spin around each other.

2.

1. 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?

1. They will accelerate toward each other.
2. *They will accelerate away from each other.
3. They will spin counterclockwise.
4. They will spin clockwise.

1. Consider the diagram below.

Which of the following best explains why the stream of water bends when the balloon is brought near it?

1. *There is an electrical attraction between the water molecules and the balloon.
2. There is gravitational attraction between the water molecules and the balloon.
3. There is nuclear repulsion between the water molecules and the balloon.
4. There is magnetic repulsion between the water molecules and the balloon.

1. What happens to the force of attraction or repulsion between two objects as the distance between them increases?

1. The force increases.
2. *The force decreases.
3. The force stays the same.
4. There is no force between them.

1. 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?

1. They will move away from each other in the same direction because one is larger than the other.
2. They will move toward each other because the charges are the same.
3. *They will move away from each other and in opposite directions because like charges repel.
4. 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?

1. series circuit, because it has two bulbs
2. parallel circuit, because the same amount of current is flowing through both bulbs
3. *series circuit, because the current is divided between the two bulbs
4. parallel circuit, because it has only one battery

9. In the circuit below, which bulb(s) would be lit?

1. *the one on top only
2. the one on bottom only
3. both bulbs would be lit
4. neither bulb would be lit

10. Consider the circuit in the diagram below.

What will happen if bulb A burns out?

1. Bulbs B and C will also go out.
2. *Bulbs B and C will stay lit and become brighter.
3. Bulb B and C will become less bright.
4. 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 CCircuit D

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. *an iron nail

B. a piece of cotton string

C. a plastic ruler

D. 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?

1. The force would be weaker.
2. *The force would be stronger.
3. The force would remain the same.
4. The force would cause the magnets to repel.

16. What would the two bar magnets in number 15do 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?

1. *Between the two magnets
2. On the left side
3. On the right side
4. At the top and bottom

18. The diagram below shows the magnetic field lines of Earth. Where is Earth’s magnetic field the strongest?

1. *At the poles
2. In the East
3. In the West
4. 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.

21.

22.

23. Consider the diagram below.

This is a diagram of a(n)

1. *Electromagnet
2. Magnet
3. Electric circuit
4. 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.

26. An electromagnet converts ______into magnetic energy.

A. heat energyB. Chemical energy

C. *Electrical energyD. Solar energy

27. Which data table most accurately indicates how the number of turns of wire affects the strength of an electromagnet?

7th Grade ScienceElectricity and MagnetismTest Review

A. *

B.

C.

D.

7th Grade ScienceElectricity and MagnetismTest Review

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.

1. Magnetic field
2. *Electric field
3. Force field
4. Laser field

31. Which data table matches the graph below that shows the relationship between magnetism and electric current?

7th Grade ScienceElectricity and MagnetismTest Review

A.

B.

C. *

D.

7th Grade ScienceElectricity and MagnetismTest Review

32.

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