(a) Define resistivity. Write an expression for the resistivity of a substance. Give the meaning of each symbol which occurs in it.
(b) State the SI unit of resistivity.
(c) Distinguish between resistance and resistivity.
(d) Name two factors on which the resistivity of a substance depends and two factors on which it does not depend.
(e) The resistance of a metal wire of length 1m is `26 Omega` at `20^(@)C`. if the diameter of the wire is 0.3mm, what will be the resistivity of the metal at that temperature?

Answer

(e) `1.84 xx 10^(-8) Omega m`,