The electric field E1 at one face of a parallelopiped is uniform over the entire face and is directed out of the face. At the opposite face, the electric field E→2 is also uniform over the entire face and is directed into that face (as shown in figure). The two faces in question are inclined at 30∘ from the horizontal, E→1 and E→2(both horizontal) have magnitudes of 2.50×104NC−1 and 7.00 × 10^4 N/C. respectively. Assuming that no other electric field lines cross the surfaces of the parallel lopiped, the net charge contained with in is