Question

A wire of length L and area of cross section A wa doubled its length by melting.If its original resistivity and resistance were p and R.What will be the new resistivity and resistance​

Answer 1

Imagine a resistor as being a cylinder of length L and cross-sectional area A turned on its side. Every material has what it called a resistivity ρ, which is the Greek letter rho. The resistance R in ohms is then given by

 

R = ρL/A

 

If we increase the length to n times its original length, assuming that the area remains constant, then the resistance also becomes n times its original value since resistance is directly proportional to the length of the cylindrical resistor.