A biological fluid was placed in a rotational cylindrical viscometer, where the outer cylinder is stationary, and the inner cylinder rotates with an angular velocity of $30$ rad$/$min$.$ Determine the torque on the inner cylinder under the following conditions: the viscosity of the fluid is $0\mathrm{.}004$ Pa$$s$,$ the radius of the inner cylinder r $=30$ mm$,$ the gap between the cylinders h $=1$ mm$,$ and the length of the gap L $=10$ cm$.$ End effects are neglected.