In: Physics
A uniform electric field with a magnitude of 6 × 10^6 N/C is applied to a cube of edge length 0.1 m as seen in Fig 22-2 above. If the direction of the E - field is along the +x-axis, what is the electric flux passing through the shaded face of the cube?
In fig- n( cap) = area vector , which is perpendicular to the surface and directed radially outward.
since electric field is along + x- axis ( as shown in fig) , so electric flux will be only for the left and right face of the cube. for other faces ( top, bottom, front, back) theta = 90 so flux = 0.
since fig is not given in the question , if shaded area along + x- axis ( ie along right face) as shown in fig:
flux = E. ds
= E *ds * cos 0 ( theta= 0 ,because E and area vector are in same direction)
= 6*106 * ( 0.1)2 * 1
= 60*103 N m2 C-1
or
if shaded area is toward left face, then
flux = E*ds*cos 180
= - 60*103 N m2 C-1