Which circle has minimum flux in the following figure? circle p circle q circle r circle s

Circle Q

Explanation:

The flux of a field through a surface is given by:

where

F is the field strength

A is the area of the surface

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 . In the formula, we see that the flux is maximum when , which occurs when the field is perpendicular to the surface, and the flux is zero when , (because ) 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

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.