Lesson 1: Summary

Lesson 1: Summary

• Magnetic Field is the region around a magnetic material or a moving electric charge within which the force of magnetism acts.
• A magnetic pole is the part of a magnet that exerts the strongest force on other magnets or magnetic material.
• Like poles (N-N or S-S) repel each other, and unlike poles (N-S) attract each other.
• Magnetic poles are always found in pairs. No matter how many times a permanent magnet is cut in two, each piece always has a north and a south pole.
• Once permanent magnets are magnetized then they hold their magnetic property for a very long time.
• An electromagnet generates a magnetic field when an electric current is provided to it and it loses its magnetism when the current is off.
• The Earth magnetic field behaves like a giant bar magnet inside the Earth.
• Magnetic field lines are imaginary lines used to represent magnetic fields.
• When we sprinkle iron filings around a magnet, the iron filings will orient themselves along the magnetic field lines.
• The strength of the field is proportional to the closeness of the lines.
• Magnetic field lines can never cross, meaning that the field is unique at any point in space.
• Magnetic field lines are continuous, forming closed loops without beginning or end.