EM: Investigating electromagnets

• Physics
• Secondary Education
• Age 13

Forces and Motion 9.3

Lesson 20. 

Investigating Electromagnets

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How are you today?

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Highlights of the Day

• investigate factors that change the strength of an electromagnets

• Values :  Responsibility and Determination

RECALL OF THE PREVIOUS LESSON

Electromagnets

Three things that are needed to make an electromagnet:

• a coil of wire
• a magnetic core inside the coil
• an electric current flowing in the coil.

Factors affecting the strength 

of an electromagnet.

• A factor is another word for a variable that will affect something. 

Factors affecting the strength 

of an electromagnet.

• The number of turns in the coil. The more turns in the coil, the stronger the electromagnet.
• The material of the core. Iron and some types of steel in the core make the strongest electromagnets.
• The current in the coil. The greater the current, the stronger the electromagnet.

What will you do to increase the strength of the electromagnet?

• Increase the number of turns on the coil.
• Use more cells to increase the current.
• Use a soft iron core in place of a steel core.

Increase the number of turns on the coil.

1

Use more cells to increase the current.

2

Use a soft iron core in place of a steel core.

3

Is soft iron really soft?

YES

NO

NOT SURE

Is SOFT iron really soft?

• Soft iron is not soft in the same way as modelling clay is soft. Soft iron is the term used for iron that is easily magnetised and also easily demagnetised.
• Demagnetised means it has lost its magnetism.

SUMMARY OF THE UNIT

Self-survey: Rate your level of understanding and participation in this lesson.

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