What is the unit of viscosity?

Options

A. Pascal
B. `Nsm^(-2)`
C. `Km^(-2)s`
D. `Nm^(-2)`

Answer

B

Explanation

SI unit of viscosity coefficient `(eta)` is `Nm^(-2)` s or `Nsm^(-2)`.
We known that, `f= eta A(dv)/(dx)`
f = force
`eta =` viscosity coefficient
`(dv)/(dx)=` velocity gradient
Now, put SI units of f = N, dx = m, A `m^(2)` and v `= ms^(-1)`
in above equation. We get, `eta = (N xx m)/(m^(2)xxms^(-1))`
`= Nm^(-2)s`
Hence, unit of `eta = Nsm^(-2)`