A point charge `Q` is moving in a circular orbit of radius `R` in the `x-y` plane with an angular velocity `omega`.This can be considered as equivalent to a loop carrying a steady current `(Qomega)/(2pi)`.A uniform magnetic field along the positive `z`-axis is now switched on, which increases at a constant rate form `0` to `B` in one second.Assume that the radius of the orbit remains constant.The application of the magnetic field induces an `emf` in the orbit.The induced `emf` is defined as the work done by an induced electric field in moving a unit positive charge around a closed loop.It is known that, for an orbiting charge, the magnetic dipole moment is proportional to the angular momentum with a proportionally constant `gamma`.
The change in the magnetic dipole moment associated with the orbit, at the end of the time interval of the magnetic field change is :

Options

A. `-gammaBQR^(2)`
B. `-gamma(BQR^(2))/(2)`
C. `gamma(BQR^(2))/(2)`
D. `gammaBQR^(2)`

Answer

B