Question

When a cylindrical tube is dipped vertically into a liquid the angle of contact is 80°. When the tube is dipped
with an inclination of 40°, find the angle of contact ?
If A liquid rises in a capillary tube, then what can be the angle of contact ?

Answer 1

The angle of contact is 80°

Given-

• When tube is dipped vertically then angle of contact = 80°

If we take a container in which liquid is filled, and a capillary tube is dipped in it then liquid rises upto h height in the tube.

In this case weight is balanced by surface tension

When tube is dipped with an inclination then also liquid rises upto h height but slant height will be different.

So pressure will be same as atmospheric pressure and both the surface meniscus will be same.

If meniscus is same then angle of contact will be same.

Angle of contact will be independent from the angle of inclination.

So angle of contact when the tube is dipped inclined is 80°