question_answer

Define electric flux. Write its SI units. A spherical balloon carries a charge that is uniformly distributed over its surface. As the balloon is blown up and increases in size, how does the total electric flux coming out of the surface change? Give reason.

Answer:

                The electric flux through a given surface area  is the total number of electric lines of force passing normally through that area. It is given by \[\Delta {{\phi }_{E}}=\vec{E}.\Delta \vec{S}=E\Delta S\cos \theta \] \[SI\] unit of electric flux\[=N{{M}^{2}}{{C}^{-1}}\] As the balloon is blown up and increases in size, the total charge on its surface remains constant. Hence, by Gauss's theorem, the total electric flux coming out of its surface remains unchanged.