The dimensional formula of a physical quantity is $[M^{a} L^{b} T^{c}]$. Then,that physical quantity is:

The dimensional formula for impulse is

The dimension of $\frac{1}{{\sqrt {{\varepsilon _0}{\mu _0}} }}$ is that of

The dimensional formula of $\sqrt{\mu_{r} \varepsilon_{r}}$ is . . . . . . .

Turpentine oil is flowing through a tube of length $l$ and radius $r$. The pressure difference between the two ends of the tube is $P$. The viscosity of oil is given by $\eta = \frac{P(r^2 - x^2)}{4vl}$,where $v$ is the velocity of oil at a distance $x$ from the axis of the tube. The dimensions of $\eta$ are

Which physical quantity has the dimensions $M{L^2}{T^{-1}}$?