Science With Codey Rocky

Tutorial 01

Electromagnetism

1.0 Introduction

All matter has an electric charge which can either be positive, negative, or zero. Opposite charges attract each other, while like charges repel. Atoms are held together by these electric forces. Atoms can gain a positive or negative electric charge during the transfer of electrons.

Fig. 1(a) A copper wire has millions of atoms with free electrons to move around [1]

Fig. 1(b) The earth’s core has churns and flow of charged matter from liquid metals [2]

When this happens, a measurable electric field will form. This field will eventually become a flowing electric current from the moment the electrically charged particles start to move. The flowing electric current always forms a magnetic field around it.

Fig. 1(b) A flow of electric current generates a magnetic field around, when voltage is applied at the ends of a wire [3]

Fig. 1(c) The earth generates its own giant electromagnetic field [2]

Fig. 1(d) The sun and other stars are sources of electromagnetic radiations [4]

The interaction between the electric and magnetic fields generates waves that transmit electro-magnetic energy into space. The waves propagate at different frequencies. These frequencies determine the intensity of the electromagnetic radiation. The low to high frequency range of the waves form what is commonly known as the Electromagnetic Spectrum.