Define modulus of rigidity. Give its units and dimensions.

Explanation

Modulus of rigidity : The ratio of tangential stress to shear strain is called modulus of rigidity. It is also known as shear modulus and is represented by (G).
`G=("shearing stress")/("shearing strain")`
`G=(F/A)/((Delta l)/(l))=(F xx l)/(A xx Delta l)=F/A xx (l)/(Delta l)=(F)/(A.theta)" "[:. theta=(Delta l)/(l)]`
Units : The SI unit of shear modulus is N `m^(-2)` and its cgs unit is dyne `cm^(-2)`
Dimensional formula is `[ML^(-1) T^(-2)]`.