Here is a problem :
Here is the solution : First we will calculate the magnetic field at any random point inside the cylinder due to rotation. Because rotating charges creates current
We will take a elemental ring of width by moving
This is basically a induced magnetic field due to rotating of charges if cylinder .
now due to this rotation, there will an electric field induced Now due to acting of electric field in ring, there will act a torque in ring
Let , due to this torque,there will be an instant maximum angular velocity in the ring
Now from here maximum angular velocity comes as
Feel free to ask anything regarding the solution and problem.
If you have another trick/method to solve this particular problem please share it in below coments.
Thanks in advance.