Magnetism and Electromagnetism

What does the distance between magnetic field lines show?

The strength of the magnetic field

What are 3 properties of induced magnets?

• do not produce their own field

• Become magnetic in the presence of a magnetic field

• When the magnetic field is removed from the induced magnet it loses its magnetism.

What are the 3 magnetic materials?

Cobalt, nickel, iron

What do magnetic field lines show?

The strength and direction of the magnetic field

What is the method of finding the shape and direction of magnetic fields using iron filings?

• gently sprinkle iron filings onto a card with a permanent magnet underneath

• Tap the card to reveal the shape

• Use a plotting compass to find the direction of the magnetic field

• The needle of the magnet points to the south pole

In the RHR what does the thumb represent

The direction of the current

In the RHR what do the fingers represent

The direction of the magnetic field

Two factors affecting the strength of the magnetic field around a current carrying wire

• magnitude of the current

• Distance from the wire

3 things to make an electromagnet

• Coil of wire

• Current through the wire

• Soft iron core

How to increase the magnetic field strength of a solenoid

• increase the current

• Increase the number of turns in the coil

• Add a soft iron core

How to induce magnetism in a magnetic material:

• place in a magnetic material

• Stroke them with another electromagnet