Let us 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 unit called Ohm. Actual cause 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 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 the specific 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