Magnetism

You will begin building on your knowledge of magnetism by exploring the magnetic fields around permanent magnets, discovering which materials are magnetic, and the Earth’s magnetic field. You will learn that electric current flowing in a wire produces a magnetic field. This will include learning about electromagnets, with a solenoid and core, and which factors affect the strength of an electromagnet. Finally you will study 3 common uses of electromagnets namely circuit breakers, electric bells and loudspeakers.

Task 2b: Make notes that:

• List the materials that are magnetic - they are attracted to magnets

• Explain what a permanent magnet is.

• Draw a diagram of the Earth’s magnetic field, showing where north and south poles are.

• Describe how a hand-held compass is made, and explain how it works

• Describe what happens when like poles from 2 magnets are held close to one another

• Describe what happens when opposite poles of 2 magnets are held close to one another

Task 2c: Watch the video showning a Gauss gun then write an explaination of how it works

Task 3c: Make notes that:

• Explain what a magnetic field is

• Explain why we use magnetic field lines

• Draw a diagram of magnetic field lines around a bar magnet. Be sure to include the arrows to show the direction of the magnetic field.

• State how we know which direction to draw the arrows on.

• Explain where around the magnet the magnetic field is the strongest and how you can tell from the diagram

• Extension: What would happen to the lines if you use a stronger magnet?

Task 3d: Watch the video to find out how we can see the effect of the magnetic field generated in the core of the Earth.

Task 4b: Make notes that:

• Describe how to make an electromagnet (name the three things you need to make it work)

• Use the information in the presentation to write a plan for an investigation to test the hypothesis that changing the numer of coilds will change the strength of an electromagnet.

  • Name the independent, the dependent and the control variables

  • Draw a diagram of the apparatus to use

  • Give a step buy step method for carrying out the investigation

  • List any risks associated with this investigation and the measures you would take to minimise these risks

• Use the planning matrix in the presentation to evaluate your investigation plan.

Task 5a:

• Complete the table

• Draw a graph, making sure you put the independent variable on the x-axis

• If you do not have graph paper, neatly draw lines with a ruler on some lined paper and do your best to make an accurate graph

• Draw a line of best fit through your scatter points on the graph

• Write a conclusion, based on the results you have analysed.

Task 5b: Watch the video

• The Death Star has created a magnetic field to attract the spacecraft in that part of the galaxy

• How would you make an electromagnet strong enough to do this?

Task 6b: Make notes that:

• Explain how a circuit breaker works and how they help to keep us safe.

• Explain how an electric bell works. Use the information in the slides and the video below to help you

• Explain how a speaker works. Use the information in the slides and the video below to help you

Complete the end of unit quiz to check you understand this topic

Have a go at these exam questions

Watch the videos for more information about why magnets are magnets and a suprising if not partcularly useful application of electromagnets.