Question

An electron enters into a uniform magnetic field of intensity of 5 T at an angle 30° with the field, experiences a force of 16 × 10–13 N. The speed of electron is​

Answer 1

Dear Student,

$$\begin{gathered} \mathrm{charge}\mathrm{on}\mathrm{electron},\mathrm{q}=1.6\times {10}^{-19}\mathrm{C} \\ \mathrm{magnetic}\mathrm{field},\mathrm{B}=5\mathrm{T} \\ \mathrm{\theta }=30° \\ \mathrm{Force},\mathrm{F}=16\times {10}^{-13}\mathrm{N} \\ \mathrm{We}\mathrm{knwo}\mathrm{that}, \\ \mathrm{F}=\mathrm{qvB}\mathrm{sin\theta } \\ \mathrm{v}=\frac{\mathrm{F}}{\mathrm{qB}\mathrm{sin\theta }} \\ \mathrm{v}=\frac{16\times {10}^{-13}}{1.6\times {10}^{-19}\times 5\times \sin 30°} \\ \mathrm{v}=\frac{2\times {10}^6}{{\displaystyle \raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.}}=4\times {10}^6\mathrm{m}/\mathrm{s} \end{gathered}$$