Two steel wires are made from the same material.
(a) The first wire has length L and resistance R1.
(b) The second wire has half the length of the first wire but three times its diameter.
(i) Derive an expression for the resistance R2 of the second wire in terms of R1.
(ii) Hence, find the ratio R2:R1.
a. (i) Derive an expression for R2 in terms of R1.
b. (ii) Find the ratio R2:R1.