Concepts Of Physics MCQ Edition [Volume 1]PhysicsSome Mechanical Properties of Matter
Steel has an elastic limit of 8 10^8 N/m ^2 and a Young modulus of 2 10¹¹ N/m ^2 . Determine the maximum elongation that can be produced in a half-metre steel wire without exceeding its elastic limit.
Options
- A1 mm
- B4 mm
- C2 mm
- D8 mm
Correct answer
C. 2 mm
Step-by-step solution
Given: Elastic limit (maximum stress), = 8 10^8 N/m ^2 Young's modulus, Y = 2 10¹¹ N/m ^2 Length of the wire, L = 0.5 m From the definition of Young's modulus: Y = Stress Strain = L / L Rearranging for maximum elongation L : L = L Y Substituting the given values: L = 8 10^8 0.5 2 10¹¹ L = 4 10^8 2 10¹¹ L = 2 10⁻³ m L = 2 mm