Question

Which statement is true about rubber, a polymeric material?[1] A.A normal rubber band breaks when the strain is greater than 1. B.A normal rubber band breaks when the strain is less than 10%. C.When a small amount of sulfur is added, to provide cross-links between molecules in rubber, the elastic limit is reduced. D.When a small amount of sulfur is added, to provide cross-links between molecules in rubber, the ultimate tensile stress is reduced.

Answer 1

Answer:

A

Explanation:

Which statement is true about rubber, a polymeric material?

A.) The normal rubber band will break when the strain is greater than 1. Because according to the srain formula,

Strain = extension / original length.

For strain to be greater than one, the extension must have been greater than the original length.

B.) A normal rubber band breaks when the strain is less than 10%. This is not true

C.When a small amount of sulfur is added, to provide cross-links between molecules in rubber, the elastic limit is reduced. Surfur increases the elastic limit

D.When a small amount of sulfur is added, to provide cross-links between molecules in rubber, the ultimate tensile stress is reduced. This is not true. Surfur increases the tensile stress of the elastic material

The correct answer is therefore A