# Magnetism. Observe: SNSN Attract or repel? Observe: SNSN Attract or repel?

## Presentation on theme: "Magnetism. Observe: SNSN Attract or repel? Observe: SNSN Attract or repel?"— Presentation transcript:

Magnetism

Observe: SNSN Attract or repel?

Observe: SNSN Attract or repel?

Observe: SN SN Attract or repel?

Observe: SN SN Attract or repel?

Observe: SN

SN Make a map of the magnetic field around the bar magnet

N S Make a map of the magnetic field around the horseshoe magnet

Try this.

What does the current in the wire do?

The magnetic field, B N S B

A current makes a magnetic field I B

I B I B This is called the right hand rule

Fields If you put a ______ in a __________ field, it will experience a force.

Fields If you put a ______ in a __________ field, it will experience a force. If you put a mass in a gravitational field, it will experience a force.

Fields If you put a ______ in a __________ field, it will experience a force. If you put a mass in a gravitational field, it will experience a force. If you put a charge in an electrical field, it will experience a force.

Fields If you put a ______ in a __________ field, it will experience a force. If you put a mass in a gravitational field, it will experience a force. If you put a charge in an electrical field, it will experience a force. If you put a magnet in a magnetic field, it will experience a force.

Oddly enough… Electrical and magnetic fields can attract and repel. Gravitational fields seem to only attract

The relationship between electricity and magnetism A moving charge affects a magnet A moving magnet affects a charge

The relationship between electricity and magnetism A moving charge affects a magnet … it makes a magnetic field A moving magnet affects a charge … it makes an electrical field

The relationship between electricity and magnetism A moving charge affects a magnet … it makes a magnetic field A moving magnet affects a charge … it makes an electrical field There is an application of the right hand rule for each of these

The relationship between electricity and magnetism A stable magnetic field affects a charge… A stable electrical field affects a magnet…

The relationship between electricity and magnetism A stable magnetic field affects a charge… … only if the charge is moving A stable electrical field affects a magnet… …only if the magnet is moving

The relationship between electricity and magnetism A stable magnetic field affects a charge… … only if the charge is moving A stable electrical field affects a magnet… …only if the magnet is moving There is an application of the right hand rule for each of these

Electromagnets A coil of wire, carrying a current makes a magnetic field. If you put the coil around a piece of iron or steel, it becomes an electromagnet.

Electromagnets A coil of wire, carrying a current makes a magnetic field. If you put the coil around a piece of iron or steel, it becomes an electromagnet. Where could you use an electromagnet?

Solenoid If a magnet can move into and out of the coil, it is called a solenoid.

Solenoid If a magnet can move into and out of the coil, it is called a solenoid. Where could you use a solenoid?

Electric motors An electric motor converts electrical energy into work, usually rotational motion. Usually, a magnet makes coil of wire rotate when a current is flowing.

Which direction is the force on the wire?

Use the right hand rule !

B = the magnetic field =index finger I = the (+) current =thumb F = force on the wire =palm

B = the magnetic field =index finger I = the (+) current =thumb F = force on the wire =palm

What is the missing vector ? I B

I B

Motors --Convert electrical energy into mechanical energy --An electric current causes a coil of wire to spin in a magnetic field --The rotational motion can do many jobs Mechanical Energy  Electrical Energy

Generators --Convert mechanical energy into electrical energy --A coil of wire spinning in a magnetic field causes an electric current --There are many ways to spin the generator Mechanical Energy  Electrical Energy

Motors --Convert electrical energy into mechanical energy --An electric current causes a coil of wire to spin in a magnetic field --The rotational motion can do many jobs Generators --Convert mechanical energy into electrical energy --A coil of wire spinning in a magnetic field causes an electric current --There are many ways to spin the generator Mechanical Energy  Electrical Energy

123456123456

Generator: If you move the wire, the force is exerted on the charge Motor: If you move the charge (a current), the force is exerted on the wire B B I Force EMF Mechanical Energy  Electrical Energy

B = the magnetic field =index finger v = velocity of moving wire =thumb EMF = force on the charge =palm

What is the missing vector ? v B

v B

v EMF

Download ppt "Magnetism. Observe: SNSN Attract or repel? Observe: SNSN Attract or repel?"

Similar presentations