Question

14.A particle of charge - and mass m enters a uniform magnetic field B at A with speed vi
at an angle a and leaves the field at C with speed v2 at an angle B as shown in figure. Then

Answer 1

a) As the magnetic field is uniform, the charge comes out symmetrically. Hence, α=β

b) v=v  0  since the speed does not change during motion in a plane perpendicular to the  magnetic field

c)r=  mv0/q B

Length of arc PQ:2r sin α =   2mv0  sinα /qB

d) T= 2πm  /qB

​Time spent inside magnetic field is  

T×  2π (2π−2α)  =  2πm/qB   × (2π−2α )   2π=  2m/  qB (π−α)