All Problems

Motion of Charged Particles in Electric and Magnetic Fields

Problem 3.382

An electron accelerated by a potential difference VV =1.0kV=1.0 \mathrm{kV} moves in a uniform magnetic field at an angle α=30t\alpha=30^{\circ} \mathrm{t} the vector BB whose modulus is B=29mTB=29 \mathrm{mT}. Find the pitch of the helical trajectory of the electron.

Reveal Answer
Δl=2π2mV/eB2cosα=2.0 cm\Delta l=2 \pi \sqrt{2 m V / e B^{2}} \cos \alpha=2.0 \mathrm{~cm}