When a weight of 10kg is suspended from a copper wire of length 3m and diamerer 0.4 mm,it's length increases by 2.4cm if the diameter of the wire is doubled then extension in the wire will be how much?

Explanation

`e prop 1/r^2 therefor e_1//e_2 = r_1^2//r_2^2 = ((0.2)/(0.4))^2 = 1/4`
`therefor `e_2 = e_1/4 = 2.4/4 0.6 cm.