The ratio of Young's modulus of elasticity of two materials (E1 to E2) is 2.5. Find the ratio of the elongations in the two bars (δlto δl2) of these materials if they are of the same length and same area and subjected to the same force P. 

This question was previously asked in
SSC JE (Civil) 2023 Official Paper-II (Held On: 04 Dec, 2023 Shift 1)
View all SSC JE CE Papers >
  1. 0.4
  2. 2
  3. 2.5
  4. 1

Answer (Detailed Solution Below)

Option 1 : 0.4
Free
Building Materials for All AE/JE Civil Exams Mock Test
14.9 K Users
20 Questions 20 Marks 20 Mins

Detailed Solution

Download Solution PDF

Concept:

As per Hooke’s law,

∵ σ = ϵ × E
Given
Two bars of unit length, i.e L1 = L2 = L

Elongation ratio , i.e δL1: δL2 = ?

Both subjected to same tensile load, i.e P1 = P2 = P

Both have the same size, i.e A1 = A2 = A

Ratio of Young's modulus of elasticity (E1 : E2) = 2.5

Calculation

Elongation of the first bar,δL1 = \({PL\over AE_{1}}\)

Elongation of the second bar, δL2 = \({PL\over AE_{2}}\)
Taking ratio,

\({\delta_{L1} \over \delta_{L2}} = {{PL\over AE_{1}}\over {PL\over AE_{2}}}\)\({E_{2}\over E_{1}} = {1 \over 2.5} \) = 0.4
Hence  the ratio of the elongations in the two bars (δl1 :δl2) of these materials = 0.4 

Latest SSC JE CE Updates

Last updated on May 28, 2025

-> SSC JE notification 2025 for Civil Engineering will be released on June 30. 

-> Candidates can fill the SSC JE CE application from June 30 to July 21.

-> The selection process of the candidates for the SSC Junior Engineer post consists of Paper I, Paper II, Document Verification, and Medical Examination.

-> Candidates who will get selected will get a salary range between Rs. 35,400/- to Rs. 1,12,400/-.

-> Candidates must refer to the SSC JE Previous Year Papers and SSC JE Civil Mock Test, SSC JE Electrical Mock Test, and SSC JE Mechanical Mock Test to understand the type of questions coming in the examination.

-> The Staff Selection Commission conducts the SSC JE exam to recruit Junior Engineers in different disciplines under various departments of the Central Government.

More Stress and Strain Questions

Get Free Access Now
Hot Links: teen patti master online teen patti flush teen patti all games