Q.
Consider a uniform electric field E=3×103i^N/C. What is the flux of this field through a square of side 10cm if the normal to its plane makes a 60∘ angle with the x -axis?
Here, E=3×103i^N/C
i.e., field is along +ve direction of x -axis.
Surface area, S=(10cm)2=102cm2 =102×10−4m2=10−2m2
When normal to the plane makes an angle of 60∘ with x -axis,
then θ=60∘ ϕE=EScosθ=3×103×10−2cos60∘ =30×21=15NC−1m2