In a gravity free space, a smooth insulating ring of radius R, with a bead having charge q is placed horizontally in a uniform magnetic field of induction `B_(0)` and perpendiuclar to the plane of ring. Starting from t=0, the magnetic field is varying with time as B(l)=B_(0)+at`, where `alpha` is a positive constant. The contact force between the ring and bead as a function of time is:

Options

A. `(alphaq^(2)RT)/(m)(2B_(0)+at)`
B. `(alphaq^(2)Rt)/(4m)(2B_(0)+at)`
C. `(alphaq^(2)Rt)/(4m)(B_(0)+at)`
D. `(4alphaq^(2)Rt)/(m)(2B_(0)+at)`