a. The strength of a uniform electric field is equal to E. What is the flux of electric field strength through a square with side l, the plane of which is located at an angle of 30◦ to the direction of the electric field?
b. When calculating the flow of electric field strength through a closed surface, the flows entering inside are taken with a minus sign, and the flows exiting outside are taken with a plus sign. Using this rule, find the negative and positive fluxes of a uniform electric field of intensity E through the closed surface of a straight trihedral prism, the height of which is h. The front face of the prism, whose width is equal to h, is perpendicular to E, and the lower face is parallel to E.
c. Prove that the flux of a uniform electric field strength through any closed surface is zero.
191