Physics - Electrostatics Question with Solution | TestHub

Consider two small elements each of length $dl=rd\theta$ symmetrically. $\pi r=l$
Resolve the elemental field intensities $\because \left|d{E}_1\right|=\left|d{E}_2\right|$ $dE=2d{E}_1\cos \theta =\frac{2Grd\theta }{r^2}\cos \theta$ $\begin{array}{rl}& \mathrm{G}=\text{ Gravitational constant }\\ & \lambda =\text{ Linear massdensity }=\frac{m}{l}\end{array}$ or $dE=\frac{2\lambda G}{r}{\int }_0^{90^{\circ }}\cos \theta d\theta =\frac{2\lambda G}{r}=\frac{2\pi Gm}{l^2}$