A conductor in an electrostatic field is an equipotential surface, and the electric field lines are perpendicular to its surface. In a non-uniform field (indicated by varying density of field lines), the side facing the stronger field region (denser lines, like point P) will accumulate induced charge opposite to the field source, and the opposite side (sparser lines, like point Q) will accumulate the same type of charge as the source. The forces on these induced charges are F = qE. Since the field strength E is non-uniform, the force on the induced charge in the stronger field region will be greater.