Question

Question no 14
We associated energy and linear momentum with electromagnetic wave. Is angular momentum present also?

Answer 1

Yes, whenever linear momentum is present,

Angular momentum also manifests itself

in fact there can be torque also due to electromagnetic field .

Thus electromagnetic field can cause a physical rotation effect .

This can be demonstrated in a coaxial cylinder solenoid system where inner cylinder has charge density + and outer cylinder has same amount negative linear charge density, and outer cylinder has a current varying with time,
  , where is charge per unit length , k = current initial value , from which current gradually reduces to 0 at a rate , b = radius of outer cylinder and a radius of inner cylinder .