Question

19. Two metallic charged spheres whose radii are \( 20 cm \) and \( 10 cm \), respectively, have each \( 150 \mu C \) positive charge. The common potential after they are connected by a conducting wire is (a) \( 9 \times 10^{6} V \) (b) \( 4.5 \times 10^{6} V \) (c) \( 1.8 \times 10^{7} V \) (d) \( 13.5 \times 10^{6} V \)

Answer 1

V = q / C =

                               (150+150)×10^-6

---

                              4πε₀(20+10)×10^-2 

= 9 × 10⁶ V

So, Option (a) is correct.