Correct Answer - Option 4 : strain is dimensionless
The strain is defined as the ratio of change in dimension to the original dimension.
- If ‘δl’ changes in the length and ‘l’ is the original length, then strain = δl/l.
Hence the unit of Strain is mm/mm.
Therefore Strain has no unit. Hence it is a dimensionless term.
- The ratio of change in length to the original length is called the longitudinal strain.
- The ratio of change in diameter/breadth to the original diameter/breadth is called the lateral strain.
- The ratio of lateral strain to longitudinal strain is called the Poisson's ratio.
- The volumetric strain of a deformed body is defined as the ratio of the change in volume of the body to the deformation to its original volume.
Shear strain is defined as the strain accompanying a shearing action. It is the angle in radian measure through which the body gets distorted when subjected to external shearing action.