Electricity and Magnetism Review

Isabella was standing directly below a power line, and her compass failed to give an accurate reading. How could she explain why her compass was not working?

• A compass works with a magnetic field, and the electric current running through the lines above it would interfere with the magnetic field.

• The compass works because of an electric field, and the electric current running through the lines above would interfere with the electric field.

• The compass works because of a gravitational field, and the magnetic current running through the lines above would interfere with the gravitational field.

• A compass works because of a magnetic field, and the magnetic current running through the power lines above it would interfere with the magnetic field below it.

Tags

NGSS.MS-PS2-3

After completing an investigation of how distance affects the strength of electric forces, you graphed your data. Imagine your graph shows that the longer the distance, the strength of the electric field is minimal. What conclusion can you draw from your data?

• The strength of the electric field is strongest at a long distance.

• The strength of the electric field is strongest at a short distance.

• The strength of the electric field is weakest at both ends of the graph.

• The strength of the electric field is strongest at both ends of the graph.

Tags

NGSS.MS-PS2-3

The image depicts two bar magnets immersed in oil that contains small needle-like particles of iron. What is the BEST interpretation of the pattern created by the iron particles?

• The pattern of iron particles is created by the north pole of one magnet facing the south pole of the other magnet.

• The pattern of iron particles is created by the south pole of one magnet facing the south pole of the other magnet because south poles attract each other.

• The pattern of iron particles is created by the repulsion of like magnetic poles, we cannot determine if the poles are north or south polarization.

• The pattern of iron particles is created by the north pole of one magnet facing the north pole of the other magnet because north poles attract each other.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

A group of students carried out an investigation in which they caused the surface of a balloon to become electrically charged by rubbing the balloon on a piece of wool. They then brought the charged portion of the balloon close to a classmate’s hair and watched as the hair stuck to the balloon. The teacher explained that this was due to the negative charge on the hair. What was the charge on the balloon?

• negative

• neutral

• no charge

• positive

Tags

NGSS.MS-PS2-3

Students conducted an investigation to compare the strength of two electromagnets by determining how many paper clips they could pick up. They constructed the two electromagnets shown, Electromagnet A (9V) and Electromagnet B (3V), and used each of them to pick up paper clips for 10 seconds.

Conclusion: Electromagnet A is stronger than Electromagnet B.

Once the students completed the investigation they replaced the 3V battery on Electromagnet B with a 9V battery and repeated the experiment; however, Electromagnet A had more coils around its nail.

What will the results be when the students repeat the experiment?

• Electromagnet B will pick up more paper clips than Electromagnet A.

• Electromagnet A will pick up more paper clips than Electromagnet B.

• Electromagnet A will pick up twice as many paper clips as Electromagnet B.

• Electromagnet A and Electromagnet B will pick up the same number of paper clips.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

You and your sister both have a small camping tent set up in the backyard. You each have two strings of lights to hang inside the tent. You power your lights with a 9-volt battery and your sister uses an extension cord and powers her lights from an electrical outlet on the deck.

What is the BEST conclusion the you can make about this situation?

• Your lights shine the brightest because your battery produces less power.

• Your lights shine the brightest because your battery produces more power.

• Your sister’s lights shine the brightest because the electrical outlet has less power.

• Your sister’s lights shine the brightest because the electrical outlet has more power.

A group of students built an electromagnet using a 9-volt battery, an iron nail and copper wire.

What can the students do to make the electromagnet stronger?

• Increase the thickness of wire used.

• Replace the iron nail with a smaller iron nail.

• Decrease the number of turns in the wire coil.

• Replace the battery with a higher voltage battery.

Tags

NGSS.MS-PS2-3

How can levitating trains support the claim that magnetic fields exist between objects exerting magnetic force on each other even when there is no physical contact?

• Levitating trains are controlled by the attraction of two similar magnetic poles being brought close together.

• Levitating trains are controlled by the repulsion of two similar magnetic poles being brought close together.

• Levitating trains are controlled by the attraction and connection of magnets on the train to magnets on the train tracks.

• Levitating trains are controlled by the repulsion and connection of magnets on the train to the magnets on the train tracks.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

Allison is working on a science activity. She takes an iron rod and wraps insulated copper wire around it. She connects the ends of the copper wire to the battery. Allison switches on the circuit and brings some paper clips near the iron rod. The paper clips are attracted to the iron rod.

Which of the following will cause the paper clips to fall off the iron rod?

• increase the current flow through the circuit

• switch on the circuit to start the current flow

• increase the copper wiring around the iron rod

• switch off the circuit to stop the electric current

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

A group of students was discussing whether the concept of magnetic fields is just a theory or if magnetic forces can be shown to exist between objects that are not touching. Some of the students were convinced that these forces only exist in theory while the rest of the students decided to prove that these forces actually exist.

How can the students prove that magnetic forces exist between objects that are not touching each other?

• Place two bar magnets on a table six inches apart with similar poles facing each other.

• Place two bar magnets on a table six inches apart with opposite poles facing each other.

• Use two magnets, one on the door and one on the door frame, to hold a cabinet door closed.

• Tape a bar magnet to the top of a toy car and use a second bar magnet to move the car without allowing it to touch the car.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5