Question

How many excess electrons must be present on each sphere if the magnitude of the force of repulsion between them is 3.33×10−21 n?

Answer 1

Answer:

The number of excess electrons on each sphere is 759

Explanation:

Given that,

distance , d = 20 cm

                    = 0.20 m

let the number of electrons is n  

Electric force (F) = k × (n × e)² /d²

3.33 × $10^{-21}$ = 9 × $10^{9}$ × (n × 1.602 × $10^{-19}$)² /0.2²

solving for n

n = 759