Question

Ratio of magnitude of electric force in air and water between an electron and proton is

Answer 1

Charge of proton and electron is same 1.6x10^-19 just change the signs

Distance is 1.6 cm convert it into meters because Physics uses MKS system

So Electrostatic Force = k(-1.6x10^–19)/(1.6/100)^2 (Attractive Force)

Answer 2

let seperation between electron and proton is r.

charge on electron = charge on proton = 1.6 × 10^-19C (let q)

so, force between electron and proton in air , F = Kq²/r²

now, we have to find force between electron and proton in water Medium.

you know, force is inversely proportional to dielectric constant of medium.

so, when we find force between electron and proton in water , force will be F' = kq²/Dr² = F/D

experimentally, dielectric constant of water , D = 80.4

so, F' = F/80.4

hence, ratio of electric force in air and water between electron and proton, F/F' = 80.4 [ this is required answer ]