MHT CET2010PhysicsMechanical Properties of Solids
Four wires of the same material are stretched by the same load. Which one of them will elongate most if their dimensions are as follows
Options
- AL=100 ~cm , r=1 ~mm
- BL=200 ~cm , r=3 ~mm
- CL=300 ~cm , r=3 ~mm
- DL=400 ~cm , r=4 ~mm
Correct answer
A. L=100 ~cm , r=1 ~mm
Step-by-step solution
L= F L A Y Because, wires of the same material are stretched by the same load. So, F and Y will be constant. aligned L & L r² L₁ &= 100 (1 10⁻³ )² &= 100 10⁻⁶ = 100 10⁻⁶ L₂ &= 200 (3 10⁻³ )² &= 200 9 10⁻⁶ = 22.2 10⁶ L₃ &= 300 (3 10⁻³ )² &= 300 9 10⁻⁶ = 33.3 10⁶ L₄ &= 400 (4 10⁻³ )² &= 400 16 10⁻⁶ = 25 10⁶ aligned We can see that, L=100 ~cm and r=1 ~mm will elongate most.