Question

Which one of the following represents the correct dimensions of the coefficient of viscosity?

1. ML^-1T^-1
2. MLT^-1
3. ML^-1T^-2
4. ML^-2T^-2

Answer 1

option 1 is correct 

From stokes law, Viscous force F = \(6\pi \eta rv\)

\( \Rightarrow \eta = {F \over {6\pi rv}}\)

\(\therefore[\eta] = {[{ML{T^{ - 2}}]} \over {[L][L{T^{ - 1}}]}}\)

\( \Rightarrow [\eta] = [M{L^{ - 1}}{T^{ - 1}}]\)