Electricity I - SS3 Physics Past Questions and Answers - page 2

Electric charge is a fundamental property of matter, which arises due to the presence or absence of electrons in an atom or molecule. Electrons have a negative charge, and protons have a positive charge, whereas neutrons have no charge. The unit of electric charge is Coulomb (C). Electric charges are responsible for the creation of electric fields, which are regions in space where electric charges experience a force. The strength of an electric field is directly proportional to the charge and inversely proportional to the distance between the charges.

The electric charge has two fundamental properties, which are as follows:

1. Like charges repel each other, whereas unlike charges attract each other.

2. Electric charge is conserved, which means that it cannot be created or destroyed but can be transferred from one object to another.

Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points, provided the temperature and other physical conditions remain constant.