a hemispherical body of radius R is placed in a uniform electric field E.what is the flux linked with the curved surface if the field is perpendicular to the base

net flux=flux of curved surface area+flux of plane

now, flux through plane=E(¶r2)cos180= -E(¶r2)......since angle is 180 because direction of field lines is opp to direction of area vector of plane surface. The field lines are in the direction of area vector of curved surface i.e the hemispherical part or curved part.

flux through CSA= E2¶r2 

thus,

 net flux= E(2¶r2 ) + (-E¶r2)

             = E¶r2

Approved