( 4 10¹⁰ ) electrons are removed from a neutral metal sphere of diameter ( 20 ~cm ) placed in air. The magnitude of the electric field (in ( N C⁻¹ ) ) at a distance of ( 20 ~cm ) from its centre is:

Step-by-step solution

Given, number of electrons removed =4 10¹⁰ ; diameter of metal sphere =20 ~cm ; distance r =20 ~cm . Therefore, Electric field = 1 4 ₀ q r² where 1 4 ₀ =9 10⁹ q= (4 10¹⁰ ) (1.6 10⁻¹⁹ )=6.4 10⁻⁹ Electric field = 9 10⁹ 6.4 10⁻⁹ (20 10⁻² )² =1440 ~N C ⁻¹