A narrow tube is placed vertically in a pan of water, and the water rises in the tube to 4 cm above the level of the pan. The surface tension in the liquid is lowered to one-half its original value by the addition of some soap. What happens to the height of the liquid column in the tube?
A) It drops or rises, but the height cannot be calculated from the information given.
B) It remains at the same height.
C) It drops to 2 cm.
D) It drops to 1 cm.

Question

Quizplus · Accepted Answer

The height of the liquid column in the tube is inversely proportional to the surface tension. When the surface tension is halved, the height of the liquid column drops to half its original height, from 4 cm to 2 cm.

A Narrow Tube Is Placed Vertically in a Pan of Water