A capillary tube of radius 1 mm is 10cm long. Whatmaximum height of wa...
h = 2T/rdg
h = (2*98)/(0.005*1000*10)
= 196/50
= 3.92 cm
that is approximately equal to 4 cm.
A capillary tube of radius 1 mm is 10cm long. Whatmaximum height of wa...
**Given Data:**
- Radius of capillary tube, r = 1 mm = 0.1 cm
- Length of capillary tube, L = 10 cm
- Height of water immersed, h1 = 5 cm
- Surface tension of water, γ = 98 dynes/cm
**To find:**
The maximum height of water that the capillary tube can hold when taken out of the water.
**Assumptions:**
- The water rises in the capillary tube due to capillary action.
- The water column in the capillary tube is in equilibrium with the atmospheric pressure.
**Formula Used:**
The height of the liquid column in a capillary tube is given by the equation:
h = (2γcosθ)/(ρgr)
Where:
- h is the height of the liquid column
- γ is the surface tension of the liquid
- θ is the angle of contact between the liquid and the capillary wall
- ρ is the density of the liquid
- g is the acceleration due to gravity
- r is the radius of the capillary tube
**Solution:**
1. We are given the surface tension of water, γ = 98 dynes/cm.
2. We know that water rises in a capillary tube due to capillary action.
3. When the capillary tube is immersed in water, the water rises to a certain height due to the adhesive forces between the water molecules and the capillary wall.
4. The angle of contact between water and the capillary wall is nearly 0°.
5. Substituting the given values in the formula, we get:
h = (2γcosθ)/(ρgr)
6. Since the angle of contact is 0°, cosθ = 1.
7. The density of water, ρ = 1 g/cm³.
8. The acceleration due to gravity, g = 980 cm/s².
9. The radius of the capillary tube, r = 0.1 cm.
10. Substituting the values in the formula:
h = (2 × 98 × 1)/(1 × 980 × 0.1)
= 2 cm
**Therefore, the maximum height of water that the capillary tube can hold when taken out of the water is 2 cm. Hence, option D is the correct answer.**
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