Exams › JEE Main › Physics
A capillary tube of radius 1 mm, open at both ends, is filled completely with water and held vertically. What length of water column remains in the tube? (Surface tension of water = 73.5 * 10⁻³ N/m, contact angle = 0 deg, g = 9.8 m/s²)
- 0.3 cm
- 3 cm
- 6 cm
- 0.03 cm
Correct answer: 3 cm
Solution
A tube open at both ends develops two menisci, so the surface tension support is doubled compared with a normal capillary rise, retaining a column of height 4T/(r*rho*g).
Related JEE Main Physics questions
- A body is in motion inside a liquid, and the viscous resistive force on it is directly proportional to its speed. What are the dimensions of the proportionality constant?
- A capillary tube has its inner surface lined with wax and is then placed in water. Relative to a clean, unwaxed capillary, how do the contact angle (θ) and the height (h) to which water rises change?
- A charged, isolated spherical soap bubble of radius r has internal pressure equal to atmospheric pressure. If the charge on the bubble is given by Xπ√(2Tε), what is the value of X?
- Two capillary tubes, one of length L and radius R and the other of length 2L and radius 2R, are joined one after the other in series. If the flow rate through a single capillary is X = πPR⁴ / 8ηL, then the combined flow rate through the series arrangement is:
- A liquid will fail to wet the surface of a solid when the angle of contact is
- A gold sphere of a given size falls through a viscous liquid and attains a terminal speed of 0.2 m/s. If the gold has density 19.5 kg/m³ and the liquid has density 1.5 kg/m³, what terminal speed will a silver sphere of the same size have in the same liquid, given that silver has density 10.5 kg/m³?
⚔️ Practice JEE Main Physics free + battle 1v1 →