Physics: Chapter 4- Electricity: Magnetic and Heating Effects

Magnetic Field

The region around a magnet or a current carrying where its magnetic effect can be felt.

Magnetic Effect of Electric Current

The phenomenon where electric current flowing through a conductor produces a magnetic field around it.

Hans Christian Oersted (1771-1851)

Discovered the magnetic effect of electricity whilst teaching in a university in Denmark and noticing the deflection of the compass needle when the circuit was completed, which was also confirmed by the scientists after he published his findings.

Electromagnet

A current carrying coil that behaves as a magnet, which also has two poles.

Ways to strengthen an electromagnet

Increase the number of cells, increase the number of turns of the coil.

Heating Effect of Electric Current

The phenomenon where electric current flowing through a conductor heats/warms it.

Factors on which heat generated in a wire depend on

Material, Thickness, length of wire and duration for which the current flows.

Voltaic cell/Galvanic cell

Contains two metal plates made of different materials (electrodes), a liquid called an electrolyte placed in a glass/plastic container. Invented by Alessandro Volta and Luigi Galvani.

Dry cells

Cells in which the electrolyte is a thick moist paste instead of a liquid.

Rechargeable batteries

Batteries that can be recharged and reused multiple times, although they too slowly wear out.

Lithium-ion (Li-ion) battery

The most common rechargeable battery which rely on special metals like lithium and cobalt.