Radius of the path (r) is given by r=qBmv \begin{aligned} \mathrm{r} &=\frac{\sqrt{2 \mathrm{mk}}}{\mathrm{eB}} \quad(\because \mathrm{p}=\mathrm{mv}=\sqrt{2 \mathrm{mk}}) \ &=\frac{\sqrt{2 \mathrm{meV}}}{\mathrm{eB}} \quad(\because \mathrm{k}=\mathrm{eV}) \ \mathrm{r} &=\frac{\sqrt{\frac{2 \mathrm{~m}}{\mathrm{e}} \mathrm{V}}}{\mathrm{B}}=\frac{\sqrt{\frac{2 \times 9.1 \times 10^{-31}}{1.6 \times 10^{-19}}(500)}}{100 \times 10^{-3}} \end{aligned} r=10−10.169.1×10−10=43×10−4 =7.5×10−4