Question

The following four wires are made of the same material. Which of these will have the largest extension when the same tension is applied?

(a) ) length = 200 cm, diameter =2 mm

(b) length = 300 cm, diameter -=3 mm

(c) length = 50 cm, diameter = 0.5 mm

(d) length = 100 cm, diameter = 1 mm

Answer 1

Correct option (c) length = 50 cm, diameter = 0.5 mm

Explanation:

 Young's modulus,

where F is the force applied, L is the length, D is the diameter and ΔL is the extension of the wire respectively. As each wire is made up of same material therefore their Young's modulus is same fol each wire. For all the four wires. Y, F (= tension) are the same.

Hence, ΔL is maximum in (c).