Question

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

• A. water will begin to overflow through the capillary
• B. angle of contact decreases
• C. angle of contact increases
• D. the meniscus completely vanishes

Answer 1

The correct option is C angle of contact increases

If the length of the tube is decreased below $5\text{cm}$ (in this case), the radius of the meniscus will increase,
$hR=h^{\prime }{R}^{\prime }$
So, when the radius of the meniscus increases, the angle of contact increases.