The corresponding fluxes are
fL= EL DS = 
ˆ
L
L
∆S
E
⋅n
=EL DS cosq = –EL DS, since q = 180°
   = –ELa2
fR= ER DS = ER DS cosq  = ER DS,   since q = 0°
   = ERa2
Net flux through the cube
Rationalised 2023-24
32
Physics
 EXAMPLE 1 11
 EXAMPLE 1