Electricity and Magnetism

​Electricity and Magnetism

​Electricity and magnetism are manifestations of a single force:

ELECTROMAGNETISM​

​

Electromagnetism is one of the fundamental forces in nature.​

​Electromagnetism is a branch of physics that studies interaction between electric and magnetic fields.

​Electromagnetism is based on the fact that the motion of electric charges can produce magnetic fields, and changing magnetic fields can produce electric currents.

​Opposite charges attract while like charges repel.

Multiple Select

All matter has an electric charge which can be

• positive

• negative

• neutral

​These electric forces bring and hold atoms together.

And when atoms gain a positive or negative charge (through the transfer of electrons) a measurable electric field will form.​

If those electrically charged particles start to move, the field will become a flowing electric current and form a magnetic field around it.​

​Applications of electromagnetism

​Fuel gauge system

Match

Match the following

• petrol

• tank

• float

• coil

benzina

serbatoio

galleggiante,

galleggiare

spirale,

molla,

bobina

• benzina

• serbatoio

• galleggiante,

  galleggiare

• spirale,

  molla,

  bobina

​A car fuel gauge system uses an electromagnet to indicate the amount of petrol that there is in the tank.

​The electric circuit consists of:

• a battery

• a variable resistor

• a permanent magnet

• a coil connected to the fuel gauge indicator​

​The coil is position in the permanent magnetic field. When electric current passes through the circuit, the coil is magnetised and turns towards the permanent magnet, adjusting the position of the indicator. The amount it turns depends on how strong the current is.

A float on the surface of the petrol in the tank is connected to the variable resistor, which controls the current flowing to the coil. ​ When the fuel level is high, a high current flows causing the indicator to turn towards the maximum position.