Three liquids of densities ρ1,ρ2 and ρ3 (ρ1>ρ2>ρ3) having the same value of the surface tension T, rise to the same height in three identical capillaries. The angles of contact θ1,θ2 and θ3 obey:
1. π2>θ1>θ2>θ3≥0
2. 0≤θ1<θ2<θ3<π2
3. π2<θ1<θ2<θ3<π
4. π>θ1>θ2>θ3>π2
A capillary tube of radius r is immersed in water and water rises in it to a height h. The mass of the water in the capillary is 5 g. Another capillary tube of radius 2r is immersed in water. The mass of water that will rise in this tube is:
1. | 5.0 g | 2. | 10.0 g |
3. | 20.0 g | 4. | 2.5 g |
When a capillary tube is dipped into a liquid, the liquid neither rises nor falls in the capillary.
a. | the surface tension of the liquid must be zero. |
b. | the contact angle must be 90∘. |
c. | the surface tension may be zero. |
d. | the contact angle may be 90∘. |
Choose the correct option:
1. | (a) and (b) |
2. | (b) and (c) |
3. | (c) and (d) |
4. | all of these |