A piece of nichrome wire of uniform circular cross-section has length 2 m and resistance 5 Ω at room temperature. The wire is uniformly stretched so that its length becomes exactly double while its volume remains unchanged.
(i) State the mathematical relation connecting the resistance of a uniform wire with its length and cross-sectional area.
(ii) Calculate the new resistance of the stretched wire.
(iii) Determine the percentage change in resistance produced by the stretching.