Year 11 - Science
Strength of an electromagnet
Electromagnetism
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
This unit explores magnetism, including permanent and induced magnets, magnetic fields, and Earth's magnetism. It covers current-induced magnetic effects, electric motors, and devices like microphones and loudspeakers, with an emphasis on models, calculations, and practical applications.
Lesson Summary
You will learn to accurately measure the strength of an electromagnet to analyse how different factors affect it.
Key Notes
- A soft iron core increases the strength of an electromagnet because it becomes magnetised when it is turned on.
- The more tightly wound the coil of wire is in an electromagnet, the stronger its magnetic field.
- The greater the current through the coil of an electromagnet, the stronger its magnetic field.
- The strength of an electromagnet is directly proportional to the current through it.
Vocabulary To Learn
- coil of an electromagnet: An insulated wire wound into the shape of a spring.
- turn of wire: A single loop of wire in a coil.
- soft iron: Very pure iron that cannot be made into a permanent magnet.
- directly proportional to: Describes the relationship between two variables, in which doubling the value of one variable doubles the value of the other.
- error bars: These show the accuracy of each measurement on a graph.
Common Mistakes To Avoid
- Digital ammeters are always accurate to the smallest amount they display.
3 Quick Questions (With Answers)
1. Explain the scientific idea in this lesson using two key points.
A soft iron core increases the strength of an electromagnet because it becomes magnetised when it is turned on. The more tightly wound the coil of wire is in an electromagnet, the stronger its magnetic field.
2. Define this scientific word and use it in context. 'coil of an electromagnet'
An insulated wire wound into the shape of a spring. Include the word in a full scientific explanation, not as a single label.
3. Correct this common scientific misunderstanding.
Mistake: Digital ammeters are always accurate to the smallest amount they display. Correction: Show pupils a copy of the specifications of the ammeters they are using that show how accurate they really are.
More Lessons In This Unit
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