Electricity and Magnetism

What causes the poles of the electromagnet in an audio speaker to repeatedly switch directions?

• a metal striker that pulls on the magnet

• a diaphragm that vibrates around the magnet

• a current that rapidly switches direction

• a device that opens and closes a circuit

Tags

NGSS.MS-PS2-5

Which would ultimately cause the armature in an electric motor to spin?

• The current in the armature stops.

• The gap in the commutator closes.

• The current in the armature is reversed.

• The commutator loses contact with the brushes.

Tags

NGSS.HS-PS2-5

NGSS.HS-PS3-5

Which parts of an electric generator are connected?

• two brushes

• two slip rings

• the armature and axle

• the armature and commutator

Beth made the chart shown.

Which headings best complete the chart?

• X: Use DC Y: Use AC

• X: Use AC Y: Use DC

• X: Powered by Current Y: Powered by Magnetism

• X: Powered by Magnetism Y: Powered by Current

Tags

NGSS.MS-PS2-3

The diagram shows a coiled wire that carries an electrical current.

What do the arrows represent?

• the magnetic field

• thermal energy

• light energy

• the electric field

Tags

NGSS.MS-PS2-3

Georgia moves an unattached piece of wire back and forth over a magnet. Which best explains what will happen?

• A current will be induced because the wire moves through a magnetic field.

• A current will not be induced because the wire moves through a magnetic field.

• A current will be induced because the wire is not part of a closed circuit.

• A current will not be induced because the wire is not part of a closed circuit.

Tags

NGSS.HS-PS2-5

Frances drew a diagram to show electromagnetic induction.

Which label belongs in the area marked X?

• Current

• Magnetic field

• Solenoid

• Force on wire

Tags

NGSS.HS-PS2-5

What happens to an iron bar when it is placed within the coils of a solenoid?

• It induces a current.

• It stops the current.

• It becomes a magnet.

• It loses its magnetism.

Tags

NGSS.MS-PS2-3

An object that is made of which material is likely to be attracted to a magnet?

• nitrogen

• iron

• paper

• plastic

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

Which shows the pieces after the magnet is cut?

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