A hemispherical body is placed in a uniform electric field E. What is the flux linked with the curved surface if the field is (a) parallel to base of the body , (b) perpendicular to base of the body and (c) perpendicular to the curved surface at every points as in figure.

Explanation

a. Number of field lines coming to the curved
surface is equal to the field lines moving away
from the surface. Hence, the flux linked with
curved surface is zero.
b. Flux passing through the plane surface = the flux
passing through the curved surface.
`phi = EpiR^2`
(positive as field lines are away from the surface)
c. `phi = E2piR^2`.