An electron moving with a velocity v =(1.0 × 10^7 m / s ) i +(0.5 × 10^7 m / s ) j enters a region of uniform magnetic field B =(0.5 mT ) j. Find the…

Radius of circular path: $\displaystyle r=\frac{m v_{x}}{e B}$ $\displaystyle r=\frac{9.1 \times 10^{-31} \times 1 \times 10^{7}}{1.6 \times 10^{-19} \times 0.5 \times 10^{-3}}$ $\displaystyle =11.38 \times 10^{-2} \mathrm{~m}$ Yes, it traces a linear path too. Linear distance during period of one revolution: $\displaystyle y=\frac{2 \pi m}{e B} \times v_{y}$ $\displaystyle =\frac{2 \times \pi \times 9.1 \times 10^{-31} \times 0.5 \times 10^{7}}{1.6 \times 10^{-19} \times 0.5 \times 10^{-3}}$ $\displaystyle =0.357 \mathrm{~m}=0.36 \mathrm{~m}$