An electric field E=(2xi^)NC−1 exists in space. A cube of side 2 m is placed in the space as per figure given below. The electric flux through the cube is ................ Nm2/C.
Answer: 16
Solution
E=2xi^ N/C. The cube spans x=2 m to x=4 m, side 2 m, so area of each face perpendicular to x is 4 m2.
At x=2: flux in =E(2)×A=(2×2)(4)=16 Nm2/C (entering, taken negative for outward convention). At x=4: flux out =E(4)×A=(2×4)(4)=32 Nm2/C.