2019:
The electric flux through a closed surface is given by:
Φ = q/ε0
In this case, the charge is at the centre of the cube, so the electric flux through any face of the cube is:
Φ = Q/6ε0
2018:
The electric field at a point due to a charge q is given by:
E = kq/r2
In this case, the point C is the centroid of the triangle, so the distance from the charge q to the point C is:
r = a/√3
Therefore, the electric field at the point C is:
E = (q/4πε0a2)√3
2017:
The electric flux through a closed surface is given by:
Φ = q/ε0
In this case, the charge is at the centre of the square, so the electric flux through the square is:
Φ = q/4πε0
