Question

Consider a Gaussian surface,cube of edge 2m with 1 corner at x=5m & y=4m.The cube lies in a region where electric field -3i-4y²j+3k N/C .What is the net charge contained by the cube?

Answer 1

Dear Student,
$$\begin{gathered} Here \\ electricfieldhasonlyyaxisdepandance \\ sochangeinfluxwillbeinonlyy-directionthroughcube \\ Sochangeinfluxthroughcube=Areaofsurface\times (4{y_1}^2-4{y_2}^2) \\ \frac{q_{in}}{{\epsilon }_0}=4\times 4(6^2-4^2)=320 \\ {q}_{in}=320\times 8.85\times {10}^{-12}C=2.832nC \end{gathered}$$
Regards