Electricity & Magnetism

An electric current will always follow ____.

• the path of least resistance

• a path toward the north pole

• a path toward the south pole

• the path that leads through insulations

Electric circuits provide energy for light bulbs. Which of these prevents the flow of electrons?

• a circuit that is closed

• a series circuit

• a circuit that is open

• a parallel circuit

A magnetic field will be detected near this circuit only if

• the wire is made of iron

• a current flows through the wire

• the wire is cooled first

• the battery contains acid

Tags

NGSS.MS-PS2-3

A device that converts mechanical energy into electricity is a

• generator

• meter

• motor

• solenoid

Tags

NGSS.MS-PS3-5

The closer together a magnet's magnetic field lines are, __

• the weaker the magnetic field

• the stronger the magnetic field

• the closer they are to the magnet's center

• the closer they are to disappearing

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

After rubbing a rubber brush on wool, Gilbert is able to use the brush to pick up small strips of paper. What causes the paper to be attracted to the brush?

• gravity

• electric current

• static electricity

• magnetism

Tags

NGSS.MS-PS2-3

In this diagram, the nail behaves like a bar magnet when current runs through the circuit. What will most likely happen when the switch is closed?

• A magnetic field should be produced

• The iron in the nail should break down

• The battery's charge should be depleted

• Rusting should be immediately observed

A magnet can generate an electric current in a wire if the magnet is close enough to the wire and if the magnet is also

• strong

• weak

• at rest

• in motion

Tags

NGSS.HS-PS2-5

Would increasing the number of batteries in a circuit that is connected to a small electric motor affect the speed of the motor, if all other variable are kept constant?

• No, because it is the magnetic force, not the electric force, that connects the motor speed.

• Yes, the motor would run faster because the increased electrical force increases the magnetic force in the motor.

• No, the speed of a motor is controlled only by the number of wire coils in the motor.

• Yes, the motor would run faster because increased current causes the motor to become warmer.

Tags

NGSS.MS-PS3-5

Which change will most likely increase the strength of a magnetic field produced by an electromagnetic?

• Reduce the number of turns of the coil

• Switch the direction in which the batter is connected

• Remove the iron nail

• Add a battery

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5