Question

Figure 4.181 shows a capillary tube $C$ dipped in a liquid that wets it. The liquid rises to a point $A$. If we blow air through the horizontal tube $H$, what will happen to the liquid column in the capillary tube?

• A. Level will rise above $A$
• B. Level will fall below $A$
• C. Level will remain at $A$
• D. It is difficult to predict

Answer 1

The correct option is A Level will rise above $A$

According to bernaulis equation the pressure and speeds are inversly proportional to each other, so if the velocity increases, the pressure will decrease and thus it generates the upward lifting force to minimize the decrease. As a result liquid comes out.