उत्तर : 1. "210 kN/mm2"
व्याख्या :

Answer: A) 210 kN/mm2 Explanation: It is useful to have a property of a material that is independent of the size of the sample and can be use to compare its elastic properties with another - this is called the Modulus of Elasticity for the material. The modulus of elasticity is defined as:   Modulus of elasticity = Stress / Strain   There are three types of moduli. They are : (a) the Young Modulus - tensile and compression longitudinal stress (b) the shear modulus - a shearing stress (c) the bulk modulus - volume changes of the specimen.