Consider a disk of mass m, radius R lying on a liquid layer of thickness T and coefficient of viscosity $\eta$. Which of the following is correct ?

For the disk to rotate at a constant angular velocity  $\omega$, we need to apply a tangential force $\frac{\eta 2\pi \omega R^3}{3T}$  at a distance of  $\frac{3R}{4}$ from the centre

The power required to rotate the disk at a constant angular velocity $\omega$  is given by  $\frac{\pi {\omega }^2\eta R^4}{2T}$

The power required to rotate the disk at a constant angular velocity $\omega$  is given by  $\frac{2\pi {\omega }^2\eta R^4}{T}$

For the disk to rotate at a constant angular velocity  $\omega$, we need to apply a tangential force $\frac{\eta \pi \omega R^3}{3T}$  at a distance of  $\frac{3R}{4}$ from the centre