1.6.1. Capillary Rise in Annular Tubes

Try these first

1. 1.

   Define capillarity.

   Hint

   Think about how water moves in a straw.

2. 2.

   What role does surface tension play in capillary rise?

   Hint

   Consider what happens at the surface of the water.

3. 3.

   What primarily drives capillary rise?

   • Pressure difference
   • Cohesion
   • Surface tension

   Hint

   Consider what occurs at the surface of the liquid.

4. 4.

   True or False: The angle of contact can affect how high a liquid rises in a tube.

   • True
   • False

   Hint

   Reflect on the beading effect of water.

5. 5.

   A glass tube has an outer diameter of 5 mm and an inner diameter of 3 mm. If the angle of contact is 30 degrees and the surface tension of water is 0.072 N/m, calculate the height of water rise.

   Hint

   Substitute known values for \\(\\sigma\\), \\(\\phi\\), \\(D\\), \\(d\\), and gravitational acceleration.

6. 6.

   Explain how increasing the inner diameter of an annular tube affects the capillary rise.

   Hint

   Reflect on how the forces balance in larger tubes.