MCQ
A solid metallic sphere has a charge $+3Q$. Concentric with this sphere is a conducting spherical shell having charge $-Q$. The radius of the sphere is a and that of the spherical shell is $b(b > a)$. What is the electric field at a distance $R(a < R < b)$ from the centre
- A$\frac{Q}{2 \pi \varepsilon_0 R}$
- B$\frac{3 Q}{2 \pi \varepsilon_0 R}$
- ✓$\frac{3 Q}{4 \pi \varepsilon_0 R^2}$
- D$\frac{4 Q}{4 \pi \varepsilon_0 R^2}$