Introduction A photocell is a technology application of the photoelectric effect. It is a device whose electrical properties are affected by light. It is also sometimes called an electric eye. A photocell consists of a semi- cylindrical photo- sensitive metal plate (emitter) and a wire …

The Internet It is a system with bilions of users worldwide. It permits and sharing of all types of information between any two or more computers connected through a large and complex network. It was started in 1960's and opened for public use in 1990's. With the passage of time…

In communication using radio waves, an antenna at the transmitter radiates of Electromagnetic waves (em waves), which travel through the space and reach the receiving antenna at the other end. As the em wave travels away from the transmitter, the other end. As the em wave travels away f…

"Communication is the act of transmission of information". Every living creature in the world experiences the need to impart or recive information almost continuously with others in the surrounding world. For communication to be successful, it is essential that the sender and th…

The Zorth Low of Thermodynamics led us to the concept of temperature that agree with our commonsense notion. Temperature is a maker of the 'hotness' of a body It determine the direction of flow of heat when two bodies are placed in thermal contact. Heat flow from the body at a hig…