Question

A uniformly charged sphere is placed inside a charged hollow sphere as shown in the figure. $O$ is the centre of hollow sphere and $C$ is the centre of solid sphere. The magnitude of charge on both the spheres is $4\left(\sqrt{\frac{3}{7}}\right)\mu C$. The electric field at point $P$ which lies just outside the hollow sphere is given by $3\alpha KN/C$. Find the value of $\alpha$. (Here, $K=\frac{1}{4\pi {\epsilon }_0}$ )

Answer 1

Answer: 1

$E_r={\vec{E}}_1+{\vec{E}}_2$
$E_r=\sqrt{E_1^2+E_2^2+2E_1{E}_2\cos \theta }$
where, $E_1=\frac{kQ}{1^2},E_2=\frac{KQ}{(\sqrt{4}{)}^2}$
and $\theta =60^{\circ }$