Question

In the case of a uniform electric field and a flat surface, the electric flux is defined as the dot product of the electric field and the area, where the direction of the area is the normal to the area pointing out of a closed region.
Consider a cube that measures 4.0 m on edge. The edges lie along the coordinate axes x, y, and z, with one corner at the origin, and the other corners having positive coordinates. A uniform and constant electric field points along the +z-axis with magnitude 5.5 N/C.

Fig. 23-27

(a) What is the direction of the area vector for the top surface of the cube?  ---Select--- +i -i +j -j +k -k
(b) What is the electric flux through the top surface?  N m²/C
(c) What is the electric flux through the front surface?  N m²/C
(d) The electric field is rotated through 30° toward the x axis. What now is the electric flux through the top surface?
N m²/C
(e) What now is the electric flux through the front surface?  N m²/C

Answer 1