+1 vote
in Farm Machinery by (38.9k points)
The length of wire is increased by 8 mm in length, when a weight of 5 kg is hung through it. If all the conditions are kept same, but radius of wire is doubled, what would be the new length of wire?

(a) 2mm

(b) 4mm

(c) 6mm

(d) 8mm

I got this question during a job interview.

My doubt stems from Strength of Materials topic in division Strength of Materials and Construction Materials of Farm Machinery

1 Answer

+2 votes
by (243k points)
selected by
 
Best answer
Right answer is (a) 2mm

Explanation: Y = \(\frac{M.g.l}{\pi.r^2 l} \)

From this relation, it is clear that l α \(\frac{1}{r^2}\), accordingly putting the radius of wire as double, the elongation will be

l = \(\frac{1}{4}\)*8 = 2 mm

Related questions

We welcome you to Carrieradda QnA with open heart. Our small community of enthusiastic learners are very helpful and supportive. Here on this platform you can ask questions and receive answers from other members of the community. We also monitor posted questions and answers periodically to maintain the quality and integrity of the platform. Hope you will join our beautiful community
...