Question

A large syringe is connected, through an infusion tube, to a smaller one. They contain colored water. What happens if we press on the plunger of the small syringe?

Answer 1

If you press on the plunger, you increase the pressure of the air, and thus the air in the small syringe escapes out, and hens the large syringe gets expanded.

Also the colored water gets filled inside the larger syringe.