A charged particle enters a uniform magnetic field with velocity vector at an angle of 45° with the magnetic field. The pitch of the helical path is p. The radius of the helix will be
Answer & explanation
Correct answer: option 2
Pitch P = $\frac{2\pi mv sin\theta}{qB} = 2\pi R$
Since R = $\frac{mvcos\theta}{qB}$
$\Rightarrow R = \frac{P}{2\pi}$