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⚛️ Physics  ·  Mechanical Properties of Solids  ·  NEET & JEE

Steel is preferred over copper for the same length and load-bearing cable application primarily because, for steel:

Answer: The Youngs modulus is higher, so it stretches less and resists deformation better.

  • A The mass density of steel is considerably lower than that of copper of equal volume
  • B The Youngs modulus is higher, so it stretches less and resists deformation better
  • C The bulk modulus of steel under compression is lower than that of copper
  • D Steel happens to have a noticeably higher Poissons ratio than copper does

Correct answer: B. The Youngs modulus is higher, so it stretches less and resists deformation better

Explanation: Steel has a higher Youngs modulus than copper, meaning it deforms (stretches) less under the same stress, making it more suitable for load-bearing applications like cables and bridges.

Stress-Strain Curve for a Ductile Metal WireStrainStresselastic limityield pointUTS (max stress)fractureSlope of the straight (elastic) portion = Young's modulus Y; the curve beyond elastic limit shows permanent (plastic) deformation

A typical stress-strain curve: the initial straight line (Hooke's Law region, slope = Young's modulus) ends at the elastic limit; beyond the yield point, deformation becomes permanent, peaking at the ultimate tensile strength before the wire finally fractures.

Concept context

Stress, strain, Hookes law, and the elastic moduli that describe how solids deform and recover under load.

Read the full Mechanical Properties of Solids notes →