Question

Notes for chapter electricity.

Answer 1

1. Introduction
Physical phenomena associated with the presence and flow of electric charge is known as electricity. Electricity and electrical phenomenon have a lot of applications in our day to day life and they also gives a wide variety of well-known effects, such as lightning, static electricity, electromagnetic induction and the flow of electrical current.

*Electricity occurs due to several types : 
 -Electric charge: a property of some subatomic particles, which determines their electromagnetic interactions. 
 -Electric current: a movement or flow of electrically charged particles, typically measured in amperes. 
 -Electric field: an especially simple type of electromagnetic field produced by an electric charge even when it is not moving (i.e., there is no electric current). The electric field produces a force on other charges in its vicinity. Moving charges additionally produce a magnetic field. 
 -Electric potential: the capacity of an electric field to do work on an electric charge, typically measured in volts.*In this chapter we will study about electricity.
 

2. Electric Charges

*Electric charge is a fundamental property like mass; length etc. associated with elementary particles for example electron, proton and many more.
*Electric charge is the property responsible for electric forces which acts between nucleus and electron to bind the atom together.
*Charges are of two kinds   
   1 negative charge   
   2 positive charge

*Electrons are negatively charged particles and protons, of which nucleus is made of, are positively charged particles. Actually nucleus is made of protons and neutrons but neutrons are uncharged particles.
*Electric force between two electrons is same as electric force between two protons kept at same distance apart i.e., both set repel each other but electric force between an electron and proton placed at same distance apart is not repulsive but attractive in nature

3. Conductors and insulators

*There is a category of materials in which electric charges can flow easily while in other materials charges cannot flow easily.
*Substances through which electric charges can flow easily are called conductors. All metals like copper, aluminum etc. are good conductors of electricity.
*Substances through which electric charges cannot flow are called insulators.
*Few examples of insulating materials are glass, rubber, mica, plastic, dry wood etc.*Presence or absence of free electrons in a material makes it a conductor or insulator.
*Conductors have free electrons which are loosely held by nuclei of their atoms whereas insulators do not have free electrons as in insulators electrons are strongly held by nuclei of their atoms.