Answer:
Circle Q
Explanation:
The flux of a field through a surface is given by:
[tex]\Phi = F A cos \theta[/tex]
where
F is the field strength
A is the area of the surface
[tex]\theta[/tex] is the angle between the direction of the field and the normal to the surface
In the figure, we see that the 4 surfaces have different orientations, so different angle [tex]\theta[/tex]. In the formula, we see that the flux is maximum when [tex]\theta=0^{\circ}[/tex], which occurs when the field is perpendicular to the surface, and the flux is zero when [tex]\theta=90^{\circ}[/tex], (because [tex]cos 90^{\circ}=0[/tex]) which occurs when the field is parallel to the surface.
In the figure, we see that circle Q is parallel to the direction of the field, so in this case the field is zero, while in all the other cases is not.
So, the correct answer is
Circle Q
