8.2.3.5-Motors vs. Generators

8.2.3.5-Electric Motors

By Jessica Freeman

By Rochelle Hogan

​Electromagnets - Things we already know...

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In Summary: ​When we change the distance we change the energy between magnets in the magnetic field.

​

~​The bigger the magnet, the stronger the magnetic field around it.

~The shorter the distance between the magnets, the stronger the magnetic field around it.

~The more coils in an electromagnet, the stronger the magnetic field.

~The thicker the coils, the stronger the magnetic field around it. ​

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

Which device converts electrical energy to mechanical energy (could be used to turn in a fan, for instance)?

• Generator

• Transformer

• Motor

Generators like the one in the image are used in cars

• alternators

  • provide electrical energy to operate the lights and other things in the car

• spark plugs

  • use electrical energy to ignite the fuel in the cylinders of the engine

​

Uses for generators​...

​Once the engine is actually running it provides the mechanical energy to turn the coil in the alternator​

By Rochelle Hogan

​

An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a coil. The current comes from a battery. The magnetic field disappears when the current is turned off. The strength of an electromagnet changes depending on the size and amount of the attached battery/batteries.  A higher voltage battery/batteries will produce a larger current through the same wire. Also, the more batteries, the more power.

​The Strength of ElectroMagnets

How can an Electric Current be Produced in a Conductor?

• In 1831, scientists discovered that moving a conductor in a magnetic field could induce an electrical current

  • there is no contact between the wire and the magnets, but the magnetic field starts the current

• Electromagnet Induction: generating electric current from the movement of a conductor through a magnetic field

  • Creates an Inducted Current

Induction of Electric Current

• Two scientists discovered the process of electric induction

  • Micheal Faraday and Joseph Henry

• Two possible setups can cause electromagnet induction

  • the Magnet remains still while the conductor moves through the magnetic field

  • The Conductor remains still while a magnet moves through it

• CHANGING the direction of movement CHANGES the direction of the current

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

​DRAW and Label -> similarities / differences

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

Multiple Choice

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

• magnetism and thermal

• electricity and magnetism

• electricity and thermal

• magnetism and radiant

Multiple Choice

What did Faraday discover about induction?

• That a changing magnetic field induces a current in a conductor.

• That electricity and magnetism were related when he noticed a current carrying conductor deflected the compass of a needle.

• That the Earth's magnetosphere deflected from the Sun known as solar winds.

• That alternating current could be manipulated with transformers.

Multiple Choice

Motors are devices that convert ____ energy into ____ energy.

• electrical; mechanical

• chemical; mechanical

• mechanical; electrical

• potential; kinetic

Multiple Select

Choose all of the motors.

Multiple Choice

Generators are devices that convert _____ energy into _____ energy.

• mechanical; electrical

• potential; kinetic

• chemical; mechanical

• electrical; mechanical

Multiple Select

Choose all of the generators.

Multiple Choice

A transformer actually transforms

• generators into motors

• magnetic field lines

• voltage

Multiple Select

Choose all of the transformers.

Multiple Choice

Which best describes how a motor works?

• When a fan blows on a wire, it causes it to spin, creating a force.

• When a fan blows on a wire, it causes it to spin, creating an electrical current.

• When a wire that carries electrical current is placed in zero gravity, the wire experiences a force.

• When a wire that carries electrical current is placed in a magnetic field, the wire experiences a force.

Multiple Choice

What is produced by moving a permanent magnet through a coil of copper wire?

• light

• electricity

• sound

• electromagnet

Multiple Choice

In an electric motor, the energy transformation begins as ---

• electrical and becomes chemical

• mechanical becomes electrical

• electrical and becomes mechanical

• mechanical and becomes chemical

Multiple Choice

What energy do you put IN to a generator?

• Thermal

• Mechanical

• Electrical

• Potential

Multiple Choice

What type of energy comes OUT of a generator?

• Electrical

• Potential

• Mechanical

• Thermal

Multiple Choice

Generators are devices that convert _____ energy into _____ energy.

• mechanical; electrical

• potential; kinetic

• chemical; mechanical

• electrical; mechanical

Multiple Choice

What kind of motor does the trolley use?

• Gasoline motor
• Electric motor
• Magnetic motor

Draw

Circle what things are different in these two models.

Drag and Drop

A ​

Placeholder

is a device that measures small amount of ​

Placeholder

.

Drag these tiles and drop them in the correct blank above

galvanometer

current/electricity

thermometer

magnetism

Open Ended

​How do you think an electric motor works?

Multiple Choice

What are the components of an electric motor?

• Circuit board, gears, springs, and lubricant
• Stator, rotor, commutator, brushes, and bearings
• Battery, wires, switch, and magnets
• Stator, rotor, commutator, brushes, and belts

Drag and Drop

Electric​ motors transform ​

Placeholder

energy into ​

Placeholder

energy.

Drag these tiles and drop them in the correct blank above

electrical

mechanical

chemical

light

Multiple Choice

What is a generator?

• a device the creates a magnetic field

• a device the turns mechanical energy into electrical energy

• a device that uses electricity

Multiple Choice

What is a transformer?

• a device that turns energy into magnetism

• a device that adjusts the energy by increasing or decreasing the voltage

• a device that has mechanical energy

Multiple Select

What are the two types of electric transformers?

• Up and down transformers
• North and south transformers
• Step-up transformer

• step-down transformer

electrical mechanical



spin



opposite

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