Question

Define electric flux. Write its SI unit. A charge q is enclosed by a spherical surface of radius R. If the radius is reduced to half, how would the electric flux through the surface change ?

Answer 1

Electric flux : Electric flux over an area in an electric field represents the total number of electric field lines crossing this area. It is denoted by `phi_(E)`.
The S.I. unit of electric flux is `Nm^(2) C^(-1)` or Vm.
The electric flux is given by
`phi_(E)= underset(S)ointvec(E).vec(ds)=q/epsi_(0)`
which is independent of the radius of sphere. Hence, the electric flux through the surface of sphere remains same.