A charged particle enters a uniform magnetic field with velocity vector at angle of `45^@` with the magnetic field. The pitch of the helical path followed by the particle is p. the radius of the helix will be

Options

A. `P/(sqrt(2)pi`
B. `sqrt(2)P`
C. `P/(2pi)`
D. `(sqrt(2)P)/(pi)`

Answer

C

Explanation

`p=(2m)/(Bq)(v cos 45^(@))=(2pim)/(Bq)( v sin 45^(@)):. (mvsin 45^(@))/(Bq)=p/(2pi)=` radius of helix