Question

Calculate the electric field when the forces is 2N and the medium is mica

Answer 1

E₀ = 5.97 10⁸ N / C

Step-by-step explanation:

Coulomb's law in a material medium is written

`F = (1)/(4\pi \epsilon ) (q_(1) q_(2) )/(r^(2) )`

ε is the electrical permittivity of the material

Electric field and force are related

F = q E

in dielectric materials such as mica there is an electric field inside the material that decreases the external field

E = E₀ /ε

where ε is the electrical permittivity of the material; in general it is tabulated in the form

`\epsilon _(r) =(\epsilon)/(\epsilon_(o))`

`\epsilon = \epsilon_(r) \ \epsilon_(o)`

we substitute

F = q E₀ / \epsilon_{r} \epsilon_{o}

`E_(o) = (F \ \epsilon_(r) \ \epsilon_(o) )/(q)`

for the case of mica it is equal to er = 5.4 and suppose a test charge equal to the charge of the electron

we calculate

E₀ = 2 5.4 8.85 10⁻¹² / 1.6 10⁻¹⁹

E₀ = 59.74 10⁷

E₀ = 5.97 10⁸ N / C