Question

If the electric filed is given by E=8 i cap+4j cap+8k cap NC^-1. Calculate electric flux through a surface of area 100cm^2 lying in the X-Y plane.​

Answer 1

Answer: Electric Flux =  0.08 Nm²C⁻¹

Explanation:

E = 8i + 4j + 8 k NC⁻¹

Surface Area dS = 100 cm² = 10⁻² m²

Since surface area lies in X-Y plane , the area vector ds is in the z axis direction.

∴ cosθ = cos [Angle between E and ds]

           = [Angle between E and z axis]

            = dirction cosine of E along z axis

             =  Ez/|E|

              = 8/$\sqrt{64 + 16 + 64}$

              = 8/12

              = 2/3

∴ Electric flux Ф = E ds cosθ

                           = 12 x 10⁻² x 2/3

                           = 0.08 Nm²C⁻¹