Answer:
The magnetic field by an moving charge 'q' moving with a velocity 'v' is given by
[tex]\overrightarrow{B}=\frac{\mu }{4\pi }\frac{q\overrightarrow{v}\times \widehat{r}}{r^{2}}[/tex]
Applying values we get
[tex]\overrightarrow{B}=\frac{4\pi \times 10^{-7} }{4\pi }\frac{1.6\times 10^{-19}\times 2.5\times 10^{7}\overrightarrow{k}\times \widehat{r}}{r^{2}}[/tex]
[tex]\overrightarrow{B}=4\times 10^{-19}\frac{(-\widehat{i}+\widehat{j})}{r^{2}}\\\\\overrightarrow{B}=4\times 10^{-19}\frac{(-\widehat{i}+\widehat{j})}{x^{2}+y^{2}+z^{2}}[/tex]
