A charged particle enters a unifrom magnetic field with velocity vector at an angle of `45^(@)` with the magnetic field . The pitch of the helical path followed by the particles is `rho` . The radius of the helix will be

Options

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

Answer

c

Explanation

`p=(2pim)/(Bq)(v cos 45^@)=(2pim)/(Bq)(vsin45^@)`
`:. (mvsin45^@)/(B_0q)=p/(2pi)=` radius of helix