If a charged particle of charge to mass ratio $\alpha$ enters in a magnetic field of strength B at a speed $\mathrm{v}=\left(2\mathrm{\alpha d}\right)\left(\mathrm{B}\right),$ then

• A

  angle subtended by the path of charge particle in magnetic field at the centre of circular path is $2\pi$.

• B

  the charge will move on a circular path and then will come out from magnetic field at some distance from the point of insertion

• C

  the time for which particle will be in the magnetic field is $\frac{2\mathrm{\pi }}{\mathrm{\alpha B}}$

• D

  angle subtended by the path of charge particle in magnetic field at the centre of circular path is $\pi /2$