# What is Capillary tube: Definition and 18 Discussions

Capillary action (sometimes capillarity, capillary motion, capillary effect, or wicking) is the process of a liquid flowing in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube, in porous materials such as paper and plaster, in some non-porous materials such as sand and liquefied carbon fiber, or in a biological cell. It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container wall act to propel the liquid.

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1. ### I Infinite flow with capillary tubes?

I was watching this YouTube video by the channel The Action Lab: At one point it shows this capillary tube phenomenon: It got me immediately thinking: Conservation of energy much? What's stopping that second tube from being bent into draining into the leftmost tube, thus creating an...
2. ### Capillary Tube Behavior in a Gravityless Environment

Homework Statement A 20 cm long capillary tube is dipled in water.The water rises up to 8cm .if the entire arrangement is put in a freely falling elevator ,the length of the water column is A)10cm B)8cm C)20cm D)4cm Homework Equations Its a theoretical sum The Attempt at a Solution...
3. ### B Why does mercury rise in a glass capillary tube despite its strong cohesion?

It's a question which come into my mind after reading related notes now and again and I can't think of plausible response to it. Given Statements: We have a container filled with mercury and a glass capillary tube placed in it . As tube's diameter become smaller mercury's height in tube will get...
4. ### Microfluidics in pressures lower than one atmosphere

Hi everyone I am trying to build an experiment with microfluidics. I have a reservoir containing a bellow. This bellow is a compensation mechanism and makes sure that the liquid (in this case water) can be pushed out of the reservoir. Before storing the fluid in the reservoir, the reservoir is...
5. K

### How does the capillary tube in refrigerators work?

How does the capillary tube decrease the pressure on the liquid when its diameter is smaller? How small diameter of capillary tube is helpful in causing more pressure drop? And how, when pressure drops, the liquid instantly cools down?
6. ### Water in capillary tube and friction

When we put an empty capillary tube in a water container, the water goes up a little bit by itself until the surface tension (ST) force is equal to its weight .This shows that unlike friction, this ST force acts individually . So if we take out the tube out of the container, and drain a little...
7. ### What happens if we put a hole in a capillary tube?

case 1)The hole is drilled before the liquid rises case 2) the hole is drilled after the liquid rises
8. ### What is the flow rate through a capillary tube?

Hi, I was wondering if there was an equation for the flow rate through a straight vertical or angled capillary tube. All I can find is how to calculate the height it rises but I would like to know how to find the rate it rises. I imagine it is not a steady rate since it must stop once it...
9. ### How to Calculate the Length of a Capillary Tube for a Drip-Irrigation Emitter

Homework Statement A drip-irrigation emitter constructed of a coiled capillary tube is inserted into the wall of a drip irrigation line with a constant water pressure of 5 psi. Compute the required length of the emitter’s capillary tube to produce an emitter dripping rate of 2 litres per...
10. ### Surface tension and capillary tube

Homework Statement A capillary tube of radius r = 0.3mm is filled with water. A water droplet is hanging on the bottom of the tube, as shown in the picture. The water level is h = 5.2cm. Estimate the radius of curvature of the droplet R. The coefficient of surface tension of water is σ =...
11. ### Surface tension - liquid rising in capillary tube

Homework Statement Homework Equations The Attempt at a Solution Honestly, I don't have any idea on this. As far as I remember, the usual practice is to equate the excess pressure equal to ##2T/R## (where T is the surface tension and R is the radius of curvature, this may be wrong...
12. ### Air Trapped in Capillary Tubes: Understanding Pressure and Volume Changes

Homework Statement Hey folks, here is a question: A thread of mercury of length 15cm is used to trap some air in a capillary tube with uniform cross-sectional area and closed at one end. With the tube vertical and the open end uppermost, the length of the trapped air collumn is 20cm...
13. ### Capillary Tube Rise: Does Water Reach Max Height & Stop?

Does the water approach the maximum height in a capillary tube with 0 velocity?I mean to say that does it go to the maximum height and just stop or perform simple harmonic motion ?Water is in equilibrium but velocity need not be 0 or is it(why?).The expression we derive for h should be for...
14. ### What Happens to Air Trapped in a Capillary Tube in Different Orientations?

Hey folks, here is a question: A thread of mercury of length 15cm is used to trap some air in a capillary tube with uniform cross-sectional area and closed at one end. With the tube vertical and the open end uppermost, the length of the trapped air collumn is 20cm. Calculate the length of the...
15. ### Finding Absolute Zero Experimentally: Investigating a Capillary Tube

We were presented with a task of calculating the temperature of absolute zero experimentally. To do this, we were given a capillary tube with one end sealed. Then we heated the tube up in a bunsen burner and quickly put the open end in some cooking oil. The oil was sucked up as the gas within...
16. ### Pressure diffence between water column in capillary tube and open vessel

Homework Statement It is known that water in a capillary will rise to a certain height, as shown in the figure. Comparing the points P and Q, which point exhibit larger pressure? a. P b. Q c. The pressure of P and Q are the same Homework Equations F_upward=2*pi*R*T*cos⁡θ W=pi*R^2*...
17. ### What is the height of water in an inclined capillary tube?

heya :D Homework Statement (Q)Water rises in a vertical capillary tube upto a length of 10 cm. If the tube is inclined at 45 degrees, the length of water risen in the tube will be <a>10 cm <b>10/(2)1/2 <c>10(2)1/2 <d>None of these Homework Equations Height raised in capillary, h =...
18. ### Capillary Tube and Surface Tension

Homework Statement A glass capillary sealed at the upper end is of length 0.11m and internal diameter 2 x 10^-5 m. The tube is immersed vertically into a liquid of surface tension 5.06 x 10^-2 N/m. To what length has the capillary to be immersed so that the liquid level inside and outside...