Concepts of band theory

An atom has electron, protons and neutrons. According to the Bohr’s atomic model theory nucleus of an atom contains protons and neutrons. Neutrons has no charge and protons have positively charged electrons moves around the nucleus in different orbits far ...

How a solar cell works?

Definition of solar cell  Solar cell is that cell which converts light energy to electrical energy. Working principal of solar cell is related to emission of light or absorption. It is an electronic device. Actually solar cell is p-n junction ...

intrinsic and extrinsic semiconductors

There are two types of semiconductors (i)  Intrinsic or pure semiconductor (ii)  Extrinsic or impure semiconductor (i)  Intrinsic or pure semiconductor: The conduction band of silicon and germanium is empty and the valence band is fully filled up with electrons ...

Distinction between insulator, conductor and Semiconductor

 1.   Insulator: Through these materials electricity cannot pass is called insulators. Plastic, glass, wood etc are the examples of insulators. The valence band of those material remains full of electrons. The conduction band of those material remains empty. The forbidden ...

Light emitting diode

What is Light emitting diode: Light emitting diode is a diode through which light emits. Popular name of light emitting diode is LED. It is short form of full name. When current flows through the LED, it becomes illuminated.  By ...

What is rectifier?

We use sinusoidal a.c. voltage in our house. A.C sinusoidal voltage changes its polarity continuously. Many electronic appliances we use in d.c voltage in our house like audio, amplifier, radio, tape, recorder etc. To operate those D.C. electronic appliance we ...

Reverse bias

 When a p-n junction p-region is connected negative terminal of a battery or a potential difference and n-region is connected with positive terminal of the battery this method of connection is called reverse bias. A circuit diagram is shown in ...

Forward bias

Definition of forward biasing When a battery or a potential difference is used to the p-region of p-n junction for making p-region positive then this supplying method is called forward bias. The positive terminal of the battery is connected with ...