What is the Unit of Strain?

Answer:- 

• Strain, which is the deformation caused to an object while it is acted upon by stress of any specific magnitude, is calculated as a ratio between the length shift caused by deformation to the initial length of the object. 
• As it is a ratio between two lengths, hence it is dimensionless and hence has no unit. 
• Similar to that, other physical quantities, such as engineering strain used to calculate the physical deformation caused to an object, is also a ratio between two different measurements of the same physical quantity, i.e. length, making it dimensionless. 
• The deformation is separated by the object’s initial measurements, which can be calculated once the initial and final length is determined.