SM 1

Whenever some external system of forces acts on a body, it undergoes some deformation. As the body undergoes some deformation, it sets up some resistance to the deformation. This resistance per unit area to deformation, is called

• strain

• stress

• pressure

• modulus of elasticity

The unit of stress in S.I. units is

• N/mm²

• kN/mm²

• N/m²

• any one of these

The deformation per unit length is called

• tensile stress

• compressive stress

• shear stress

• strain

The unit of strain is

• N-mm

• N/mm

• mm

• no unit

Strain is equal to, where l =Original length, and δ = Change in length.

• δ l+l

When a body is subjected to two equal and opposite pushes, as a result of which the body tends to reduce its length, the stress and strain induced is compressive.

• True

• False

When a body is subjected to two equal and opposite pulls, as a result of which the body tends to extend its length, the stress and strain induced is

• compressive stress, tensile strain

• tensile stress, compressive strain

• tensile stress, tensile strain

• compressive stress, compressive strain

When a body is subjected to two equal and opposite forces, acting tangentially across the resisting section, as a result of which the body tends to shear off across the section, the stress and strain induced is

• tensile stress, tensile strain

• compressive stress, compressive strain

• shear stress, tensile strain

• shear stress, shear strain

Which of the following is a proper sequence?

• proportional limit, elastic limit, yielding, failure

• elastic limit, proportional limit, yielding, failure

• yielding, proportional limit, elastic limit, failure

• none of the above

Hook's law holds good up to

• yield point

• elastic limit

• plastic limit

• breaking point