The electric field in the region of space shown is given by N/C where y is in m.What is the magnitude of the electric flux through the top face of the cube shown?
A)90 N . m2/C
B)6.0 N.m2/C
C)54 N . m2/C
D)12 N . m2/C
E)126 N.m2/C

Question

The electric field in the region of space shown is given by N/C where y is in m.What is the magnitude of the electric flux through the top face of the cube shown?  
A)90 N . m2/C 
B)6.0 N.m2/C 
C)54 N . m2/C 
D)12 N . m2/C 
E)126 N.m2/C

Quizplus · Accepted Answer

The electric flux through the top face of the cube is given by the dot product of the electric field and the area vector of the top face. The area vector of the top face is in the positive y direction and has a magnitude of 0.1 m x 0.1 m = 0.01 m². Therefore, the electric flux through the top face is:

Φ = E⋅A = (9 N/C)⋅(0.01 m²) = 0.09 N m²/C = 54 N/C (since flux is also measured in N m²/C)

So the best choice is C.

The Electric Field in the Region of Space Shown Is