Define electric flux. Write its SI unit. Gauss' law in electrostatics is true for any closed surface, no matter what its shape or size is. Justify this statement with the help of a suitable example.
a) Electric flux is the product of electric field and area. Its SI unit is N m²/C.
b) Electric flux is the product of charge and electric field. Its SI unit is C/m.
c) Electric flux is the product of charge and area. Its SI unit is C m.
d) Electric flux is the product of electric field and charge. Its SI unit is N/C.
