9. A conducting sphere of radius R is given a charge Q. The electric potential and the electric field at the centre of the sphere respectively are ?

A conducting sphere of radius R is given a charge Q. The electric potential and the electric field at the centre of the sphere respectively are ?

(a) Zero and \( \frac{Q}{4\pi\varepsilon_0 R^2} \)

(b) \( \frac{Q}{4\pi\varepsilon_0 R} \) and Zero

(c) \( \frac{Q}{4\pi\varepsilon_0 R} \) and \( \frac{Q}{4\pi\varepsilon_0 R^2} \)

(d) Both are zero

Answer :  (b) \( \frac{Q}{4\pi\varepsilon_0 R} \) and Zero