AKS 10C: Electromagnets, Generators, and Motors

AKS 10c: Electromagnets, Generators and Motors

Multiple Choice

Which fundamental forces govern the behavior of matter and energy?

• Gravity and Magnetism

• Electricity and Magnetism

• Heat and Light

• Sound and Friction

Motors: Electrical Energy Mechanical Energy

• Electrical energy is used to create a current in an armature (the coil)

• The armature is in a magnetic field and has its own magnetic field due to the current flowing through it

• The armature turns so that its magnetic field lines up with the magnetic field of the magnet

• A moving magnetic field causes a voltage to be created/induced

• If there is a complete circuit, this voltage will result in a current flowing

​

Electromagnetic Induction

1. Using a stronger/bigger magnet

2. ​Moving the magnetic field faster

3. More windings/loops in the coil

​

Induced voltage can be increased by...

Generators: Mechanical Energy Electrical Energy

• Mechanical energy is used to turn a rotor attached to an armature (coil)

• The armature is in a magnetic field

• As the wire is turned, it experiences a changing magnetic field

• This results in a voltage and current

• Input: Electrical energy (battery)

• Output: Mechanical energy (coil turns)

• Motor parts: battery

Motors only

• ​Input: Mechanical energy (turn the coil)

• Output: Electrical energy (voltage and current)

• Motor parts: device to be powered

​​Generators only

Parts:

Magnet

Armature

Both

Multiple Choice

Generators are devices that convert _____ energy into _____ energy.

• chemical; mechanical

• mechanical; electrical

• electrical; mechanical

• potential; kinetic

Multiple Choice

What device is made of coils of wire with an electrical current passing through it in order to generate a magnetic field?  

• Electromagnet 

• Generator

• Electron Magnet 

• Motor

Multiple Choice

Electric motors are devices that convert _____ energy into  _____ energy.

• electrical; mechanical

• mechanical; electrical

• chemical; potential

• mechanical; kinetic

Multiple Choice

What two forces are required for generators and electric motors to work?

• magnetism and thermal

• electricity and thermal

• electricity and magnetism

• magnetism and radiant

Multiple Choice

The voltmeter is at 0 in this image. How would you manipulate the experiment to create electricity (measured in volts)?

• Flip the magnet around so the North pole is facing out
• Move the magnet back and forth
• Take the magnet out
• Add more coils around the paper cylinder

Multiple Choice

How could the experimenter increase the amount of electricity being induced by this experiment?

• Increase the number of coils

• Decrease the number of coils

• Flip the magnet around

• Nothing, the amount of electricity cannot be increased

Multiple Select

Select all of the materials that make good insulators.

• rubber

• steel

• copper

• wood

• plastic

Match

If I build electromagnets using nails made of different metals, then I think the copper nail will pick up the most paperclips. Match the experimental variables.

• independent variable

• dependent variable

• constant

nails of different metals

number of paperclips picked up

battery

• nails of different metals

• number of paperclips picked up

• battery

Dropdown

Wrapping the wire around the nail more times would ​

Select answer

the magnetic field. 

Reorder

If I build electromagnets using nails made of different metals, then I think the copper nail will pick up the most paperclips.

Put my investigation steps in order.

• Using nails made of different metals, wrap each nail with 25 coils of the same wire.

• Connect the end of the wire to a battery.

• Hold the electromagnet over a pile of paperclips.

• Count the number paperclips picked up.

• Repeat 3 times with each nail.

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5