Physics 2011 JAMB Past Questions - Question 8: If a tube of small radius opened at both ends is placed in a liquid ,the liquid will

Correct Answer

C

Explanation

When a tube with a small radius is opened at both ends and placed in a liquid, the behavior of the liquid in the tube will depend on a few factors, including the relative height of the liquid in the tube compared to the surrounding liquid, the surface tension of the liquid, and the contact angle between the liquid and the tube's material.

1. Capillary Action: If the liquid wets the tube (i.e., the contact angle between the liquid and the tube's material is less than 90 degrees), and the liquid level inside the tube is lower than the surrounding liquid level, capillary action can occur. This means that the liquid will rise inside the tube due to surface tension. The height to which the liquid rises depends on the tube's radius and the properties of the liquid.

2. No Capillary Action: If the liquid does not wet the tube (i.e., the contact angle is greater than 90 degrees), or if the liquid level inside the tube is higher than the surrounding liquid, then capillary action will not occur. In this case, the liquid inside the tube will remain at the same level as the surrounding liquid.

In summary, whether the liquid rises inside the tube or not depends on the wetting properties of the liquid and the relative heights of the liquid inside the tube and the surrounding liquid. If capillary action does occur, the liquid will rise inside the tube due to surface tension forces.