Two point like charges ${\text{Q}}_1\hspace{0.17em}\hspace{0.17em}\mathrm{and}\hspace{0.17em}\hspace{0.17em}{\mathrm{Q}}_2$ are positioned at points 1 and 2.  The field intensity to the right of the charge $Q_2$ on the line that passes through the two charges varies according to a law that is represented schematically in figure. The field intensity is assumed to be positive if its direction coincides with the positive direction on the x-axis. The distance between the charges is $l.$