Electric Flux

      Theoretically, the lines of force emanating from a charge are infinite. Faraday suggested that the electric field should be assumed to be composed of very small bunches containing a fixed number of electric lines of force. Such a bunch or a closed area is called a tube of flux.

Note : The total number of lines of force or tubes of flux in any particular electric field is called as the electric flux.

     This is represented by the symbol Ψ. similar to charge, unit of electric flux is also coulomb C.

One coulomb of electric flux is defined as that flux which emanates from a positive charge of one coulomb.

      In general, if the charge on a body is ±Q coulombs, then the number of tubes of flux or total electric flux, starting or terminating on it is also Q.

     So, for a charge of ±Q coulombs,