Question

A load of 2 kg resulted an elongation of 1mm in a wire of 3 m length with 1 mm diameter. What will be the Young’s modulus of wire?

(a) 7.484*10^10 Pa

(b) 9.484*10^10 Pa

(c) 6.317*10^10 Pa

(d) 7.484*10^20 Pa

I have been asked this question during an interview for a job.

I'd like to ask this question from Strength of Materials topic in section Strength of Materials and Construction Materials of Farm Machinery

Answer 1

Correct option is (a) 7.484*10^10 Pa

For explanation I would say: Cross-sectional area of wire = πr^2 = π*(0.5 x 10^-3)^2 m^2

Y = \(\frac{F.L.}{A.l}\) = (2*9.8*3)/[π*(0.5*10^-3})^2*10^-3

Y = 7.484 x 10^10 Pa