Figure shows two capacitors connected in series and joined to a cell. The graph shows the variation in potential as one moves from left to right on the branch containing capacitors.

As the two capacitors are connected in series combination, the charge on both the capacitors will be same.

The capacitor having lower potential drop will have higher capacitance.

From the graph we can conclude that the potential drop across C₁ is more than that of C₂. So the capacitance of C₁ is less than the capacitance of C₂.