Loading presentation...

Present Remotely

Send the link below via email or IM

Copy

Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

DeleteCancel

Make your likes visible on Facebook?

Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.

No, thanks

Y8 Magnets

No description
by

Luke Whiting

on 13 June 2016

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Y8 Magnets

MAGNETS
Magic?
Or Science?
In the back of your books, write down your favourite magic trick (Don't worry if you don't know how it works)
Today's learning objectives:
Observe the effects of magnets.
Describe what happens when magnets are bought together.
Explain your observations.
Magnets Circus!
You will have 5 minutes to complete each activity
Sort the pictures into things that use magnets and those that don't.
How does the pen levitate?
Investigate the bar magnets.
Try out the super magnets.
Investigate the annular (ring) magnets.
Make a sculpture using the magnetic plate.
Copy the correct statements into your books.
The pen contains a magnet, and so does the holder. When the pen is in the right place, the north poles are aligned, as are the south poles, repelling the pen into the air!
Opposite poles attract
Like poles repel
North pole
South pole
The correct sentences are:
Magnetism is a force.
Magnets have ends that are called poles.
The force of magnetism attracts or repels.
The poles of a magnet are named north and south.
Poles that are the same repel.
Poles that are different attract.
Uses magnets
Does not use magnets
Lesson 1
What are magnets?
Plenary:
Think back to your favourite magic trick

- Could magnetism be part of the trick?
- How could magnetism have been used?
Lesson 2
How do magnets work?
Today's learning objectives:
Explore the magnetic fields of different types of magnets.
Explain how magnetism is caused by domains.
Starter questions (Answer in the back of your books)

What does it mean for a material to be magnetic?
Name as many magnetic materials as you can.
If a piece of iron has become magnetised, that means it has become a permanent magnet. Iron is able to be magnetised due to the domains found in its stucture.
The three magnetic elements:
Iron (Fe), Nickel (Ni) and Cobalt (Co)

Iron is the only one that can be
magnetised.

What do you think magnetised means?
Iron's structure is made of crystals called domains. Each has a magnetic moment.
In unmagnetised iron, the domains point in random directions meaning there is no overall magnetic field - they all cancel out!
In magnetised iron, the domains all point in the same direction. This means that they all add together and create a magnetic field.
If you apply a magnetic field to a piece of iron, it begins to the line up the domains. If you do this repeatedly, the iron will become magnetised!
We've been talking about magnetic fields, but what are magnetic fields?
Magnetic fields show the lines of force around a magnet. For example, here is the magnetic field around a bar magnet:
WHAT DO YOU NOTICE?
The arrows go North South!
How do we plot these magnetic fields?
With iron filings...
...or plotting compasses
Your task:


Investigate magnetic fields using these methods.
Copy the three diagrams into your books and complete them with the magnetic fields.
Lesson 3
Is the Earth a magnet?
Today's learning objectives:
Describe the Earth's magnetic field.
Describe and explain how to determine North using simple equipment.
Starter:
On your desk is a piece of paper. Draw on it which direction you think North is. A prize is on offer for the closest one!
Look at the magnetic field lines for Earth. What type of magnet does it look like?
Yes, the Earth really is a magnet!
That's right, it looks like a bar magnet!

So how could we use this to find out which way is North?
Using a compass of course!

The needle of a compass is a tiny magnet which is free to spin on an axis. It aligns itself to the Earth's magnetic field.

Question:
The compass's North pole points to the Geographical North Pole. What does this tell you about the Earth's magnetic poles?
North pole of compass
South pole of compass
The Earth's magnetic North is actually geographically the South pole! Be careful to remember that!
Turn to page 18 of your Physics Friend 'Marooned in the Desert'
You are stranded on a desert island and only have the listed materials. You need to work out which way is North (geographic North!)
Write a story to describe and explain how you would build a device to determine North!
Two interesting phenomena relating to the Earth's magnetic field!
Aurora Borealis
Solar flares
Lesson 4

What is electromagnetism?
Starter
How many words can you make out of:


Rules:
1) Words must be three or more letters
2) English words only (no names of people)
3) You can only use each letter as many times as it appears for each word
ELECTROMAGNETS
Describe how to create an electromagnet.
Design an investigation to test the strength of an electromagnet.
When a current is passed through a wire, a magnetic field is generated.

The direction of the current determines where the north and south poles are.

This is what we call an electromagnet
The simplest electromagnet can be constructed from a battery and a wire.
We wrap the wire into coils to concentrate the magnetic field.
We use an iron nail as this makes the electromagnet stronger.
The switch means that we can turn the electromagnet on and off
You are now going to make your own electromagnet and test it with paperclips.
Plenary:
Next lesson we are going to investigate how we can change the strength of an electromagnet. Now you need to design an investigation to see if changing the current through the coils changes the strength of the electromagnet.
Your plan must include:
An aim (what are you trying to find out)
What are your independent and dependent variable?
A prediction (what do you think will happen to the DV when you change the IV)
What are your control variables and how will you control them?
An equipment list.
A diagram of your equipment.
A method.
A blank results table ready for you to write your results into.
Lesson 5
How can we change the strength of an electromagnet?
Carry out an investigation to test the strength of an electromagnet.
Describe how to increase the strength of an electromagnet
An aim (what are you trying to find out)
What are your independent and dependent variable?
A prediction (what do you think will happen to the DV when you change the IV)
What are your control variables and how will you control them?
An equipment list.
A diagram of your equipment.
A method.
A blank results table ready for you to write your results into.
Your plan must include:
Starter: Complete the planning of your investigation
When you think you're ready, show me your plan and if it gets approved you can start the investigation
There are three ways to increase the strength of an electromagnet

Add a soft iron core
Increase the current through the coil
Increase the number of turns on the coil
What did we find?
Lesson 6

What use are electromagnets?
Starter question:

Can you think of a use of an electromagnet in a scrapyard?
Two other major uses of electromagnets
Disadvantage:

They require electricity to run
Advantage:

They can be varied in strength easily
Advantage:

They can be turned on and off
(cc) photo by medhead on Flickr
Reed

switches
Electric

bells
A reed switch is a small glass vial with two iron contacts inside. Normally, they are apart but when you bring a magnet close, they attract each other and close the switch.
Reed relays are used in cars where we want to keep the driver isolated from the high voltage supply of the engine!
Sort these statements into the correct order and write them in your books:
this sequence continues until the bell-push is released.
current flows through the electromagnet.
the current stops flowing and switches off the electromagnet.
this movement breaks the circuit at X.
the soft-iron armature is attracted to the electromagnet.
when the bell push is pressed the circuit is completed.
the hammer hits the gong.
the spring pulls the armature back and contact is made at X.
THE ELECTRIC BELL
Lesson 7
Could it be magic?
Today you are going to prepare your magic trick!

Remember, it must use magnets or electromagnets!
By the end of the lesson, you must:
Know what your trick is going to be
Handed a list of equipment you will need for next lesson to the teacher

By the start of next lesson, you must:
Have your trick prepared and your stage set
Have prepared your tricks choreography
Full transcript