r=0.15 m, E< E₀
The dielectric strength of air E₀ =3 •10⁻³ V/m
E=q/4πε₀r² =>
q=4πε₀r²E = 4πε₀r²E₀=
= 4π•8.85•10⁻¹²•0.15²•3 •10⁻³=7.5•10⁻¹⁵ C
What is the maximum charge that can be put on a conducting sphere of radius 15 cm if it is not to spark? That is, the electric field at its surface cannot exceed the dielectric strength of air.
b) What is the sphere's voltage at this charge?
1 answer