A copper rod A B of length l is rotated about end A with a constant angular velocity . The electric field at a distance x from the axis of rotation is

Step-by-step solution

In circular motion, net force on the particle is given as F_ c = m v² r =m ² r where, is angular speed. When the rod rotates, electrons in it also rotates which produce electric field E at a distance x . So, force on electron, F_ e =e E This force provide the centripetal force, i.e., F_ e =F_ c or e E=m ² x or E= m ² x e