Physics Elasticity ( Mechanical Properties of Solids ) Young’s Modulus and Breaking Stress MCQ (Single Correct)

A steel wire is suspended vertically from a rigid support. When loaded with a weight in air, it expands by L a and when the weight is immersed completely in water, the extension is reduced to L w . Then relative density of the material of the weight is

A
B
C
D

Share this question

For Instagram sharing, use “Apps” on mobile or copy the link.

Text Solution

Verified by Experts
The correct answer is:
A

It is given that the extended length in air is and the reduced length in water is .

We have to find the relative density of the weight. The ratio of longitudinal stress to longitudinal strain is called young's modulus of elasticity. Young modulus is given by the following formula.

Here, F is the force, l is the initial length of the wire, A is the area of cross-section, and is the change in the length of wire.

So, we can write the young's modulus for both air and water.

Now, we know that young's modulus is constant for the material, i.e., equation (1) is equal to equation (2).

Let us further simplify this.

We know, density is mass divided by volume.

Prepare Smarter with CGP Edu

Get practice questions, solutions, and test series in one place.

Write a Review

Share your experience with this question and solution.

Commentary

Send your comment, doubt, correction, or feedback to admin.

Student Reviews

What students say about this solution

No reviews yet. Be the first to write a review.

Similar Questions

Explore conceptually related problems

CG
CGP Question Assistant Question Bank + AI Help
Hi! Type your question or upload one screenshot. First I will search related questions from CGP Edu Question Bank. If none match, type YES and I will solve it with AI.
Upload only one screenshot at a time. Flow: Question Bank first → If not matched, type YES for AI solution.