A charged particle of mass m and charge q moves with velocity v at an angle $ heta$ to a uniform ma

Question

A charged particle of mass m and charge q moves with velocity v at an angle $	heta$ to a uniform magnetic field B. What is the pitch of its helical path?

Professor PC Thomas Classes · Answer

Pitch is the distance travelled along the magnetic field in one period. $p = v_{\parallel} T = (v \cos	heta) 	imes (\frac{2\pi m}{qB}) = \frac{2\pi m v \cos	heta}{qB}$.