which of the following materials has maximum elasticity?

Out of the given materials, Steel has the maximum elasticity.

Here's why:

• Elasticity: This is the property of a material to regain its original shape after deformation when the applied stress is removed.
• Stiffness: A stiffer material generally has higher elasticity. It requires a greater force to deform the material, and it tends to return to its original shape more completely after the stress is released.
• Material comparison:
  • Steel: Steel is a strong and stiff material with a high elastic modulus. This means it can withstand a large amount of stress before deforming, and it will spring back to its original shape effectively.
  • Rubber: Rubber is known for its elasticity, but it's a less stiff material compared to steel. It can be easily stretched or deformed, but it may not completely recover its original shape after significant deformation.
  • Copper: Copper is a ductile metal that can be bent or shaped without breaking. However, it doesn't have the same level of elasticity as steel. Once deformed beyond a certain point, it may not fully return to its original shape.
  • Sponge: Sponges have a porous structure and may exhibit some degree of shape recovery after compression. However, they are not very elastic compared to steel. They can deform permanently if squeezed too hard.