Electromagnets, Generators, and Motors

Energy and Motion

• What you know:

• 1. Magnetic force can produce motion. For example, magnets move together or apart when they are close.

• 2. An electric current in a wire produces a magnetic field. So, a magnet can move a wire with a current, just as it would move another magnet

Electric Motors

• An electric motor is a device that uses an electric current to turn an axle

• An electric motor transforms electrical energy into mechanical energy that is used to do work

• Examples of electric motors occur in many household items such as washing machines and blenders

Generators

• An electric generator is a device that transforms mechanical energy into electrical energy

• A generator uses motion in a magnetic field to produce current

• Most of the electrical energy we use comes from generators

Multiple Choice

The place on a magnet where the force it exerts is the strongest is called

• a magnetic pole

• a magnetic field line

• a domain

Multiple Choice

What is the magnetic attraction or repulsion of a magnet called?

• the magnetic domain

• the magnetic field

• the magnetic pole

• the magnetic force

Multiple Choice

The space in which the magnetic effects exists is called

• the magnetic field

• the magnetic equator

• the magnetic material

Multiple Choice

Paper clips and staples are attracted to magnets because paper clips and staples are

• permanent magnets

• temporary magnets

• magnetic materials

• magnetic domains

Match

Match the following: Read each vocabulary definition and match it correctly to the vocabulary terms.

• Kinetic energy

• Convert

• Potential energy

• Transfer

Energy involving movement

To change from one type to another

Energy that is being stored in an object or stored

To move from one object to another or one place to another

• Energy involving movement

• To change from one type to another

• Energy that is being stored in an object or stored

• To move from one object to another or one place to another

Multiple Choice

LOOK AT THE IMAGE:

Ramon puts two magnetic toy trains very close to each other on a track. What will happen next, and why?

• The trains will move closer to each other because the magnetic force will pull the trains together.

• The trains will not move because the magnets are not touching.

• The trains will move away from each other because the magnetic force will push the trains apart.

• The trains will move away from each other because the magnets are not touching.

Multiple Choice

LOOK AT THIS IMAGE: Based on the two magnetic objects, what type of magnetic forces are we observing?

• Kinetic energy

• Attracting

• Repelling

• Potential energy

Multiple Choice

LOOK AT THE IMAGE:

Based on the magnetic field line diagrams, what will happen next with these two set of magnets?

• The magnets in Set 1 will repel, and the magnets in Set 2 will attract.

• The magnets in Set 1 will attract, and the magnets in Set 2 will repel.

• The magnets in Set 1 will not move, and the magnets in Set 2 will attract.

• In the both sets, the magnets will attract.

Multiple Choice

What happens when the North pole of a magnet interacts with another magnet's north pole?

• attract
• repel

Multiple Choice

True or False:  The Earth is a giant magnet

• True
• False

Multiple Choice

Which of the following is true about a bar magnet?

• Its magnetic field is strongest near its center.

• It is surrounded by a magnetic field.

• The north pole is stronger than the south pole.

• The south pole is stronger than the north pole.

Multiple Choice

Earth acts like a giant magnet because its center is made up MOSTLY of

• granite

• limestone

• iron

• nickel

Multiple Choice

If you cut a magnet in half, what happens to the poles?

• One half gets the North Pole, the other half gets the South Pole
• Both halves get only a North Pole
• Both halves get only a South Pole
• Both halves get a North pole and a South Pole

Multiple Select

A _________________________ is the invisible force that surrounds a magnet.

• bar magnet

• a gravitational force

• a magnetic field

• gravity

Multiple Choice

What do the lines around this magnet represent?

• North Pole
• South Pole
• Magnetic Declination
• Magnetic Field

Multiple Choice

Magnetic NORTH is actually geographic _________

• SOUTH
• NORTH
• EAST
• WEST

Multiple Choice

A magnet has a _______ pole and a _______ pole.

• north, south

• east, west

• positive, negative

• red, blue

Multiple Choice

These objects would...

• Attract

• Repel

• No reaction

Multiple Choice

These objects would...

• Attract

• Repel

• No reaction

Multiple Choice

What is the role of the copper wire in this motor?

• It carries the flow of electrons.

• It powers the motor.

• It creates a magnetic field.

• It makes it look nice.

Multiple Choice

Motors are devices that convert ____ energy into ____ energy.

• electrical; mechanical

• chemical; mechanical

• mechanical; electrical

• potential; kinetic

Multiple Choice

Generators are devices that convert _____ energy into _____ energy.

• mechanical; electrical

• potential; kinetic

• chemical; mechanical

• electrical; mechanical

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 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

A student built a prototype of a simple electromagnet using a nail, some length of wire, and a battery with the goal of using it to lift three paperclips.When the student first tested this prototype, it could only lift one paperclip.

What design change would increase the magnetic field strength of this electromagnet so that it would lift three paper clips?

• Remove the nail from within the coil.

• Move the battery closer to the nail.

• Increase the number of loops in the coil.

Multiple Choice

What kind of magnet can be turned on and off?

• refridgerator magnet
• electromagnet
• magnetite
• iron

Multiple Choice

What would happen if you took one end of the wire off the battery?

• The nail will be a magnet.

• The nail would no longer be a magnet

• Nothing will happened.

• The nail will heats up.

Multiple Choice

What is the device seen here?

• generator

• electric motor

• electromagnet

• magnet

Multiple Choice

Surrounding every magnet is a __________  __________.

• magnetic field

• electrical current

• another magnet

• an enemy

Multiple Choice

What can you use to make an electromagnet?

• Battery, nail and string 

• Battery, pencil and wire

• Wire, battery and iron ore (nail)

• Peanut butter, lampshade, hand sanitizer

Multiple Choice

What happens to the strength of an electromagnet as you add more coils around it?

• Increases

• Decreases

• Stays the same

• Stops completely

Multiple Choice

How are electromagnets different from magnets?

• magnets can be turned on/off
• you can turn an electromagnet on/off
• magnets are more powerful
• magnets have a North and South pole

Multiple Choice

Which rule do we use to predict the direction a current carrying wire will move in a magnetic field?

• Fleming's Left Hand Rule
• Fleming's Right Hand Rule
• Faraday's Left Hand Rule
• Faraday's Right Hand Rule

Multiple Choice

Thumb and first finger represent .......

• magnetic field, force

• force, current

• force, magnetic field

• current, force

Multiple Choice

If a conductor is wound into a coil and a current is passed through it creating a magnetic field, what is it known as?

• Bar Magnet

• Solenoid

• Polarnoid

• Transformer

Multiple Choice

If the current is going up on the front side of the coil then what side of the electromagnet is north?

• Up
• Down
• Left
• Right