List the factors on which the resistance of a cylindrical conductor depends and hence write an expression for its resistance. (b) How will the resistivity of a conductor change when its length is tripled by stretching it?

List the factors on which the resistance of a cylindrical conductor de

1.	List the factors on which the resistance of a cylindrical conductor depends and hence write an expression for its resistance. (b) How will the resistivity of a conductor change when its length is tripled by stretching it?
Answer» Solution :The RESISTANCE of a cylindrical conductor i.e., a wire ( R) is (i) directly proportional to its length L, (ii) inversely proportional to its cross section area A and (iii) depends on the nature of material of wire MATHEMATICALLY, `R prop L/A or R=(rho.L)/A` Here , p is known as the resistivity of given material . It is defined as the resistance offered by a unit cube of given material when current flows PERPENDICULAR to the opposite FACES.