@rahulraj

SEE, U WANT AN EXPLANATION FOR CHARGE KEPT AT CENTRE OF THE EDGE. NOW IF THE CHARGE IS KEPT AT THE CENTRE OF THE EDGE , ONLY Q/4 CHARGE WILL BE INSIDE THT CHARGE BECAUSE TO COMPLETELY COVER THT CHARGE V WILL REQUIRE FOUR SUCH CUBES.HENCE THE FLUX THROUGH ALL THE FACES WILL BE

 

THIS IS THE TOTAL FLUX PASSING THROUGH ALL THE FACES. NOW SINCE THE CHARGE IS IN CONTACT WITH TWO FACES , NO FLUX WILL PASS THROUGH THEM, HENCE THIS TOTAL FLUX WILL PASS THROUGH REMAINING FOUR FACES.

HENCE FLUX THROUGH EACH FACE WILL BE

hope u can understand the solution now

RATE IF SATISFIED OR U CAN ASK FURTHER.