If liquid level falls in a capillary then radius of capillary will

(1) Increase                     

(2) Decrease

(3) Unchanged                 

(4) None of these

Water rises to a height \(\mathrm{h}\) in a capillary at the surface of earth. On the surface of the moon, the height of water column in the same capillary will be:
1. \(\mathrm{6h}\)                           
2. $\frac{1}{6}\mathrm{h}$
3.  \(\mathrm{h}\)                             
4. \(\mathrm{zero}\)

Two capillary tubes of the same diameter are put vertically one each in two liquids whose relative densities are 0.8 and 0.6 and surface tensions are 60 and 50 dyne/cm respectively Ratio of heights of liquids in the two tubes $\frac{{\mathrm{h}}_1}{{\mathrm{h}}_2}$ is

(1) $\frac{10}{9}$

(2) $\frac{3}{10}$

(3) $\frac{10}{3}$

(4) $\frac{9}{10}$

In a capillary tube experiment, a vertical 30 cm long capillary tube is dipped in water. The water rises up to a height of 10 cm due to capillary action. If this experiment is conducted in a freely falling elevator, the length of the water column becomes:

Kerosene oil rises up the wick in a lantern

(1) Due to surface tension of the oil

(2) The wick attracts the kerosene oil

(3) Of the diffusion of the oil through the wick

(4) None of the above

Water rises against gravity in a capillary tube when its one end is dipped into water because

(1) Pressure below the meniscus is less than atmospheric pressure

(2) Pressure below the meniscus is more than atmospheric pressure

(3) Capillary attracts water

(4) Of viscosity

There is a horizontal film of soap solution. On it, a thread is placed in the form of a loop. The film is pierced inside the loop and the thread becomes a circular loop of radius \(R.\) If the surface tension of the loop is \(T,\) then what will be the tension in the thread?

1. \(πR^{2} / T\)
2. \(πR^{2} T\)
3. \(2 πRT\)
4. \(2 RT\)
$$

A large number of water drops each of radius r combines to have a drop of radius R. If the surface tension is T and the mechanical equivalent of heat is J, then the rise in temperature will be

(1) $\frac{2\mathrm{T}}{\mathrm{rJ}}$

(2) $\frac{3\mathrm{T}}{\mathrm{RJ}}$

(3) $\frac{3\mathrm{T}}{\mathrm{J}}\left(\frac{1}{r}-\frac{1}{R}\right)$ 

(4) $\frac{2\mathrm{T}}{\mathrm{J}}\left(\frac{1}{r}-\frac{1}{R}\right)$

In a surface tension experiment with a capillary tube, water rises upto 0.1 m. If the same experiment is repeated on an artificial satellite, which is revolving around the earth, water will rise in the capillary tube upto a height of-

(1) 0.1 m

(2) 0.2 m

(3) 0.98 m

(4) Full length of the capillary tube

The correct curve between the height of depression h of liquid in a capillary tube and its radius is

1. 

2. 

3. 

4.