Physical Science:

Until now the physics we have learnt was for something that we could touch, see, roll, flow, etc. But now we are going to learn the physics which could only be experienced and felt. It is invisible and intangible. But it is everywhere in our daily life. Light bulbs, electronic devices, thunderstorm, etc. cannot be possible without it. Electricity and magnetism are completely separate phenomena which form the basis of electromagnetism. Electricity and magnetism both are related to charges. At dark night, when you quickly take your woolen sweater off, you can see the spark light and may also have felt the static electricity pulling your clothes. You may have experienced static shock on your car door handle after a long drive. Ancient Greeks discovered that when an amber (a hard translucent fossilized resin) was rubbed with a piece of fur, a force was created that caused the fur and the amber to attract each other. If one amber rod rubbed with fur would be brought close to another amber rod rubbed with the fur, they repel each other. Similarly, two rubbed pieces of fur would also repel each other. This experience suggested that there were two types of an electric property; this property eventually came to be called electric charge.