Electrical Resistance

We have explained here what is resistance and what is the basic theory behind it.

[cicymarymathew]

nice video. which software have you used to create?

[andrii]

Let's discuss about the basic concept of electrical resistance.

Electrical resistance is the opposition to the flow of electrons in a given material. It is measured in units called ohm. Actual pause of electric current is the flow of free electrons in a material and resistance is the opposition offered by this material to the flow of free electrons.

Resistance is directly proportional to the length of the material and inversely proportional to the area of the cross section of the material through which the current flows.

The resistance offered by conducting materials like silver copper and aluminium is low, whereas resistance offered by some other conducting materials like nichrome tungsten etc is very high. All these materials are called conducting materials, however the values of resistivity of these materials are different.

The resistance R of a material is expressed as R equals to rho times l by A, where rho is the resistivity, l is the length and A is the cross-sectional area of the conducting material. The resistivity rho is also called thenspecific resistance of the material.

The most conducting material silver has the lowest value of resistivity that is 0.016 into 10 to the power minus 6 ohm - m. After silver, copper is the most conducting. The resistivity or specific resistance of copper is somewhat more than that of silver that is 0.018 into 10 to the power minus 6 ohm - m. That is to say copper is less conducting than silver.