4.7.2.1

4.7.2.1 Electromagnetism

4.1.3 National and global energy resources

Content

When a current flows through a conducting wire a magnetic field is produced around the wire. The strength of the magnetic field depends on the current through the wire and the distance from the wire.

Shaping a wire to form a solenoid increases the strength of the magnetic field created by a current through the wire. The magnetic field inside a solenoid is strong and uniform.

The magnetic field around a solenoid has a similar shape to that

of a bar magnet. Adding an iron core increases the strength of the magnetic field of a solenoid. An electromagnet is a solenoid with an iron core.

WS 2.2

Students should be able to:

  • describe how the magnetic effect of a current can be demonstrated
  • draw the magnetic field pattern for a straight wire carrying a current and for a solenoid (showing the direction of the field)
  • explain how a solenoid arrangement can increase the magnetic effect of the current.
  • (Physics only) Students should be able to interpret diagrams of electromagnetic devices in order to explain how they work

WS 2.2 Plan experiments or devise procedures to make observations, produce or characterise a substance, test hypotheses, check data or explore phenomena.

(Physics only) WS 1.4 Explain everyday and technological applications of science; evaluate associated personal, social, economic and environmental implications; and make decisions based on the evaluation of evidence and arguments.


Resources

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Practicals

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Safety

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