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

• modulus of elasticity

• stress

• strain

• pressure

The unit of stress in S.I. units is

• kN/mm²

• any one of these

• N/mm²

• N/m²

The deformation per unit length is called

• shear stress

• tensile stress

• strain

• compressive stress

The unit of strain is

• no unit

• N-mm

• mm

• N/mm

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

• δ/l + l

• δl/l

• δl

• l/δl

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

• tensile stress, tensile strain

• tensile stress, compressive strain

• compressive stress, compressive strain

• compressive stress, tensile 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

• shear stress, shear strain

• shear stress, tensile strain

• compressive stress, compressive strain

Which of the following is a proper sequence?

• yielding, proportional limit, elastic limit, failure

• elastic limit, proportional limit, yielding, failure

• proportional limit, elastic limit, yielding, failure

• none of the above

Hook's law holds good up to

• plastic limit

• yield point

• breaking point

• elastic limit