A student was plotting a graph for electric field due to a uniformly charged thin spherical shell of radius R. at different point and got confused. Which of the following graphs is the correct one?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2)
$\phi \vec E.d\vec A=\frac{Q}{ε_0}$ [Given]
$E\phi d\vec A=\frac{Q}{ε_0}$
for $r<R$, Q eue inside a Gaussian surface is 0. Therefore, $\phi_E=0$
for $r>R$,
$E.4πr^2=\frac{Q}{ε_0}$ [Area of sphere = $4πr^2$]
$E=\frac{1}{4πε_0}\frac{Q}{r^2}⇒E∝\frac{1}{r}$