JEE Main20262 April 2026Morning ShiftPhysicsElectrostaticsActual
Two charged conducting spheres S₁ and S₂ of radii 8 cm and 18 cm are connected to each other by a wire. After equilibrium is established, the ratio of electric fields on S₁ and S₂ spheres are E_ S₁ and E_ S₂ respectively. The value of E_ S₁ E_ S₂ is _______.
Options
- A3 2
- B2 3
- C4 9
- D9 4
Correct answer
D. 9 4
Step-by-step solution
When two conducting spheres are connected by a wire, charge flows until their potentials become equal. V₁ = V₂ k Q₁ R₁ = k Q₂ R₂ The electric field on the surface of a conducting sphere is given by E = k Q R^2 , which can be written as E = V R . Since V₁ = V₂ , we have: E_ S₁ R₁ = E_ S₂ R₂ E_ S₁ E_ S₂ = R₂ R₁ Given R₁ = 8 cm and R₂ = 18 cm: E_ S₁ E_ S₂ = 18 8 = 9 4 Answer: 9 4