A particle with charge Q, moving with a momentum p, enters a uniform magnetic field normally. The magnetic field has magnitude B and is confined to a region of width d, where `d lt P/(BQ)`. The particle is deflected by an angle `theta` in crossing the field. Then

Options

A. sin `theta=(BQd)/p`
B. `sin theta =p/(BQd)`
C. `sin theta =(Bp)/(Qd)`
D. `sin theta = (pd)/(BQ)`

Answer

A

Explanation

A to D is part of circle with centre C and radius CD=r
mv=p=BQr
`r=p/(BQ)`
sin `theta=(ED)/(CD)=d/r=(BQd)/p`