Consider a uniform electric field E=`3xx10^(3) hati` N/C (a) what is the flux of this field thriought a square of 10 cm on a side whose plane is parallel to the yz plane (b) hwhat is the flux through the same a `60^(@)`m angle with the x axis

Explanation

Here, given square is in yz-plane. Hence, its area vector `vecA_(1)` will be perpendicular to yz-plane as shown in the figure. Here, electric field points along +X axis. Electric flux passing through above square is,
`phi_(1) = A_(1)E cos theta_(1)`
`=l^(2)E cos0^(@) (therefore vecA_(1) || vecE)`
`=(0.1)^(2) (3 xx 10^(3))`
`therefore phi = 30 Nm^(2)//C`
(b)
Here, in this case electric flux passing through given square is,
`phi_(2) = A_(2)Ecos theta_(2)`
`=(0.1)^(2) (3 xx 10^(3)) (1/2)`
`= 15 Nm^(2)//C`