A uniform metallic wire of initial length l0 and resistance R0 is stretched uniformly until its length becomes 1.5l0. The process is carried out at room temperature so that any rise in temperature of the wire may be neglected.
(i) Assuming that the volume of the wire remains constant during stretching, calculate the new resistance R1 in terms of R0.
(ii) Will the resistivity of the material change because of this stretching? Give a reason for your answer.
(iii) Mention two practical situations where changing the resistance of a conductor without altering its material is useful.