Electricity and Magnetism

ELECTROMAGNETISM​

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Electromagnetism is one of the fundamental forces in nature.​

​Opposite charges attract while like charges repel.

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.​

• a battery

• a variable resistor

• a permanent magnet

• a coil connected to the fuel gauge indicator​

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.