A copper wire LM is fused at the end M to an iron wire MN. The copper wire has length 0.9m and cross-sectional area
0.9 x 106m2. The iron wire has length 1.4m and cross-sectional area
1.3 x 106m². When the compound wire is stretched, its total length
increases by 0.01m. Calculate:
(i) the ratio of the extensions of the two wires,
(ii) the extension of each wire,
(iii) the tension applied to the compound wire
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