The electric flux f through a hemisphere surface of radius R, placed in a uniform electric field of intensity

E parallel to the axis of its circular plane is:

(a) 2 p RE (b) 2 pR2E (c) pR2E (d) (4/3) pR3E

Electric Flux through any surface

´ component of surface ^

to direction of electric Field

=EΠR²

since it is placed in uniform e field therefore net charge enclosed is 0 and therefore net flux is zero

i.e. flux through circular part + flux through hemi spherical part = 0

flux through circular part = - flux through hemi spherical part

                                   = e * 2pr^2 ( area of hemisphere = 1/2*4pr^2 = 2pR^2 )

hence b is correct