(ઇલેક્ટ્રૉનનો વિજભાર $=1.6 \times 10^{-19}\,C$)
\(\Rightarrow E=\left(\frac{e B r}{m}\right) B\)
\(\Rightarrow m=\frac{e B^{2} r}{E}\)
\(\Rightarrow \mathrm{m}=\frac{\left(1.6 \times 10^{-10}\right)(0.5)^{2}\left(0.5 \times 10^{-2}\right)}{100}=2 \times 10^{-24}\, \mathrm{kg}\)