Effect of Temperature on Resistance

What is effect of temperature on resistance?Resistance of material change with the change in temperature. The effect of temperature on resistance varies according to the type of material (1) Thus the resistance of a pure metal (e.g copper, aluminum )increase with increase of temperature. ...Read More

what is Conductivity?

What is conductivity? The reciprocal of resistivity of a conductor is called conductivity.It is denoted by the symbol σ. If a conductor has resistivity ρ ,then its conductivity is given by σ. =1/ρ =L/RA The unit of conductivity is mho m-1 or siemen meter ...Read More

What is EEG?

What is EEG?Electroencephalography, or EEG, is a neurological test that uses an electronic monitoring device to measure and record electrical activity in the brain.Special sensors (electrodes) are attached to your head and hooked by wires to a computer. EEG measures voltage fluctuations resulting from ...Read More

What is Sag and tension?

What is Sag and tension ?In a overhead transmission line conductor are supported at the towers or at the pole for low voltage transmission lines. The conductor are pulled and string effected. When the conductor are supported in this manner ,it will sag or ...Read More


What is electric polarization?When insulating material with relative permittivity (or dielectric constant) Eo is inserted into an initially charged parallel plates of a capacitor. Then negative charges appear on the left face and positive charges on the right face of the dielectric  The phenomenon ...Read More


In early 1821, Thomas Seebeck searched experimentally for a relation between electricity and heat. He joined two wires of two dissimilar metals to form a circuit. He discovered that if one junction is heated to a high temperature, and the other junction remained at ...Read More

Potentiometer:Working ,Application?

A potentiometer is a null type resistance network device for measuring potential differences.For the accurate measurement of potential difference, current and resistance the potentiometer is one of the most useful instruments. Its principle of action is that an unknown emf or P.D. is measured ...Read More