• # question_answer A point charge is located at 0. There is a point P at a distance r from it. The electric field at point P is 500 V/m and a potential of 3000 V. Then the value of r is A)  6m                                         B)  12m C)  24 m                     D)         36 m

Electric field due to a point charge $E=\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{q}{{{r}^{2}}}$ Electric potential due to a point charge$V=\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{q}{r}$ Dividing, $\frac{E}{V}=\frac{1}{r}$ $\Rightarrow$               $r=\frac{V}{E}=\frac{3000}{500}=6\,metre$