World of Physical Science

  ELECTRIC CURRENT AND CIRCUIT       We are familiar with air current and water current. We know that flowing water constitute water current in rivers. Similarly, if the electric charge flows through a conductor (for example, through a metallic wire), we say that there is an electric current in the conductor. In a torch, we know that the cells (or a battery, when placed in proper order) provide flow of charges or an electric current through the torch bulb to glow. We have also seen that the torch gives light only when its switch is on. What does a switch do? A switch makes a conducting link between the cell and the bulb. A continuous and closed path of an electric current is called an electric circuit. Now, if the circuit is broken anywhere (or the switch of the torch is turned off ), the current stops flowing and the bulb does not glow.      How do we express electric current? Electric current is expressed by the amount of charge flowing through a par...

Electricity       Electricity has an important place in modern society. It is a controllable and convenient form of energy for a variety of uses in homes, schools, hospitals, industries and so on. What constitutes electricity? How does it flow in an electric circuit? What are the factors that control or regulate the current through an electric circuit? Here, we shall attempt to answer such questions. We shall also discuss the heating effect of electric current and its applications.     Electricity in simple words is just study of charges. And it is divided into two different forms :- 1). Static electricity  2). Current electricity      Static electricity :- It is also known as Electrostatics. It is the study of charges at rest means when the charges are not able to move from there place. From simple experiment we can learn this also in your childhood you have done this before. Take a plastic scale or pen and rub it with your hairs and a...