Answer to Question #308271 in Physics for George

Question

Calculate the electric flux through a rectangular surface of dimensions 20cm × 10cm, placed with its positive normal making an angle of 30° with a uniform electric field of 30 × 10^-3 N/C.

Answer 1

The electric flux

$$\Phi=EA\cos\theta\\ =30*10^{-3}\:{\rm N/C*0.2*0.1\: m^2}*\cos 30^\circ\\ =5.2*10^{-4}\:\rm N\cdot m^2/C$$