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(2pi)`
B. `sqrt2p`
C. `(P)/(2pi)`
D. `(sqrt(2)p)/(pi)`

Answer

C

Explanation

`p=p=(2pim)/(Bq)(vcos45^(@))=(2pim)/(Bq)(vsin45^(@))`
`:. (mvsin45^(@))/(Bq)=(p)/(2pi)`
= radius of helix.