Question

When a capillary tube of glass is dipped in mercury, then:

• A. mercury level rises in tube
• B. mercury rises in tube and come out
• C. mercury level in tube decendes
• D. level of mercury neither ascends or descends

Answer 1

Answer: (C)

mercury level in tube decendes

The liquid which wets the wall of tube rises in the tube and the liquid which does not wet the wall of the tube descends in the tube. For example, when a glass capillary tube is dipped in water, water rises in the tube and the shape of water meniscus in concave, similarly when a glass capillary tube is dipped into mercury; mercury descends in the tube and shape of mercury meniscus is convex.