Final answer:
The electric flux through a spherical surface when the charge is at a distance of r/2 away from the center is 4*pi*k*q/r.
Step-by-step explanation:
The electric flux through a surface is given by the product of the electric field and the area of the surface. Using Gauss's law, we can find the electric flux through a spherical surface when the charge is at a distance of r/2 away from the center. The electric field at a distance r/2 from the center of a point charge is given by the equation E = k*q/(r/2)^2. The surface area of the spherical surface is 4*pi*(r/2)^2. Therefore, the electric flux through the surface is given by the equation Φ = E*A = k*q/(r/2)^2 * 4*pi*(r/2)^2 = 4*pi*k*q/r.