Electromagnetism

This lesson covers:

  1. What 'electromagnetism' is, and how it works
  2. How electromagnetism is created in wires, coils, solenoids, and electromagnets
  3. The four ways to increase the strength of an electromagnet

Which of the following is correct?

When an electrical current flows through a material, a magnetic field is always produced

When an electrical current flows through a material, a magnetic field is produced only if that material is a metal

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Illustration showing the right hand rule for determining the direction of the magnetic field induced by a flowing current.

force / current / magnetic


The right hand rule can tell us the direction of the magnetic field induced by a flowing current.


In the right hand rule, the thumb is placed following the same direction as the is travelling, and the fingers are the curled in the direction of the field lines.

current
magnetic

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Diagram showing two wires with current flowing to the right and magnetic field lines around them, labeled A and B.

The above diagram shows two wires with current flowing to the right.


Using the right hand grip rule, which of the two shows the correct direction of the magnetic field lines, A or B?

A

B

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Diagram showing the electromagnetic field around a coil of wire.

The above object can be called:

(Select all that apply)

A solenoid

A cuboid

A trapezoid

An electromagnet

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In an electromagnet, a current is required to produce the magnetic field.


When the current is switched off, the magnetic field:

Changes direction

Disappears

Remains the same

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Describe the four ways to increase the strength of an electromagnet.

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