KCET2022PhysicsElectrostatics
Two tiny spheres carrying charges 1.8 C and 2.8 C arc located at 40 ~cm apart. The potential at the mid - point of the line joining the two charges is
Options
- A2.1 10^5 ~V
- B1.3 10^4 ~V
- C3.6 10^5 ~V
- D3.8 10^4 ~V
Correct answer
A. 2.1 10^5 ~V
Step-by-step solution
Charge on first sphere, q₁=1.8 C =1.8 10⁻⁶ C Charge on second sphere, q₂=2.8 C =2.8 10⁻⁶ C Distance between the two spheres, r=40 ~cm Distance between mid-point and each sphere r₁=r₂=20 ~cm =0.2 ~m Electric potential at mid-point due to both charged sphere aligned V & =V₁+V₂= 1 4 ₀ q₁ r₁ + 1 4 ₀ q₂ r₂ & =9 10^9 1.8 10⁻⁶ 0.2 +9 10^9 2.8 10⁻⁶ 0.2 & =9 10^3(9+14)=2.07 10^5 ~V 2.1 10^5 ~V aligned