If momentum [P] , area [A] and time [T] are taken as fundamental...

We know, Viscosity=Pascal$‐$second

Let \left[η\right] ={P}^{x}{A}^{y}{T}^{z} = \left[{M}^{1}{L}^{- 1}{T}^{- 1}\right]

$⇒ {\left[{M}^{1}{L}^{+ 1}{T}^{- 1}\right]}$^{x}{\left[{L}^{2}\right]}^{y}{\left[{T}^{1}\right]}^{z} = {M}^{1}{L}^{- 1}{T}^{- 1}$</p><p>$⇒ {M}^{x}{L}^{+ x + 2y}{T}^{- x + z} = {M}^{1}{L}^{- 1}{T}^{- 1}$</p><p>From above, we have </p><p>$x = 1x + 2y = - 1 - x + z = - 1$</p><p>Solving above three equations, we get </p><p>$y = - 1 and z = 0$</p><p>So, Viscosity$= \left[{P}^{1}{A}^{- 1}{T}^{0}\right]