Question

In a capillary rise experiment, the water level rises to a height of 5 cm. If the same capillary tube is placed in water such that only 3 cm of the tube projects outside the water level, then ____________.

Options

• water will begin to overflow through the capillary

• angle of contact decreases

• angle of contact increases

• the meniscus completely vanishes

Answer 1

In a capillary rise experiment, the water level rises to a height of 5 cm. If the same capillary tube is placed in water such that only 3 cm of the tube projects outside the water level, then angle of contact increases.

Explanation:

As hr = h' r',

∴ When h decreases, r increases

∴ Angle of contact increases.