Tube of Insufficient Length

Q. Liquid rises to a height of $2\text{cm}$ in a capillary tube. The angle of contact between the solid and the liquid is zero. The tube is depressed more now so that the top of the capillary is only $1\text{cm}$ above the liquid. Then, the apparent angle of contact between the solid and the liquid is:

1. ${60}^{\circ }$
2. $0^{\circ }$
3. ${30}^{\circ }$
4. ${90}^{\circ }$

Q. Two narrow bores of diameter $5.0\text{mm}$ and $8.0\text{mm}$ are joined together to form a U-shaped tube open at both ends. If this U-tube contains water, what is the difference in the level of two limbs of the tube.

$\text{Take surface tension of water,}T=7.3\times {10}^{-2}{\text{Nm}}^{-1}$
$\text{angle of contact}=0$
$g=10{\text{ms}}^{-2}$
$\text{density of water}=1.0\times {10}^3{\text{kgm}}^{-3}$

1. $4.97\text{mm}$
2. $3.62\text{mm}$
3. $5.34\text{mm}$
4. $2.19\text{mm}$

Q. If the length of a tube is less and cannot accommodate the maximum rise of liquid, then

1. Liquid will form a fountain
2. None of the above
3. Liquid will not rise
4. The meniscus will adjust itself so that the water does not spill

Q. A U tube is made of two capillary tubes of diameter $0.5\text{mm}$ and $1.0\text{mm}$ respectively. It contains $H_{2}O$. Find the difference in the levels of water between the two arms of the U tube. (Surface tension of $H_{2}O=75\text{dynes/cm}$ and $g=980{\text{cm/s}}^2$).

1. $2.4\text{cm}$
2. $2.6\text{cm}$
3. $2.8\text{cm}$
4. $3\text{cm}$

Q. In a capillary rise experiment, the water level rises to a height of $5\text{cm}$. If the same capillary tube is placed in water such that only $3\text{cm}$ of the tube projects outside the water level, then:

1. water will begin to overflow through the capillary
2. the meniscus completely vanishes
3. angle of contact decreases
4. angle of contact increases

Q. A certain number of spherical drops of a liquid of radius r coalesce to form a single drop of radius R and volume V. If T is the surface tension of the liquid then 1. Energy =4VT(1/r - 1/R) is released 2. Energy =3VT(1/r + 1/R) is released 3. Energy =3VT(1/r - 1/R) is released 4. Energy is neither released nor absorbed

Q. When a capillary tube is dipped in a liquid, the liquid rises to a height $h$ in the tube. The free liquid surface inside the tube is hemispherical in shape. The tube is now pushed down so that the height of the tube outside the liquid is less than $h$. Then

1. the liquid will come out of the tube like in a small fountain
2. the liquid will ooze out of the tube slowly
3. the liquid will fill the tube but not come out of its upper end
4. the free liquid surface inside the tube will not be hemispherical

Q.

The lower end of a capillary tube is dipped into water and it is seen that the water rises through 7.5 cm in the capillary. Find the radius of the capillary. Surface tension of water = 7.5 × 10^-2 N m^-1. Contact angle between water and glass = 0°. Take g = 10 m s^-2.

1. 2 × 10^-3 m

2. 2 mm

3. 0.2 mm

4. 0.4 mm

Q.

Water rises upto 10 cm height in a long capillary tube. If this tube is immersed in water so that the height above the water surface is only 8 cm, then

1. Water rises upto upper end and forms a spherical surface

2. Water only rises upto 6 cm height

3. Water flows out continuously from the upper end

4. Water does not rise at all

Q. If a $10\text{cm}$ long capillary tube with $0.2\text{mm}$ internal diameter open at both ends is slightly dipped in water having surface tension $80\text{dyne/cm}$, then:
[$g=981{\text{g/cm}}^2$]

1. Height to which water level will rise will be $16.31\text{cm}$.
2. Height to which water level will rise will be equal to length of capillary.
3. Radius of curvature of meniscus will be $0.163\text{mm}$.
4. Radius of curvature of meniscus will be $0.0163\text{mm}$.

Q.

When a capillary is dipped in water, water rises to a height h. If the length of the capillary is made less than h, then

1. The water will not rise

2. The water will come out

3. The water will not come out

4. The water will rise but less than height of capillary

Q. The inside diameters of the two arms of a U-tube are $1.00mm$ and $1.5mm$ respectively. Now if it is partially filled with water having surface tension of $0.078N/m$ and zero contract angle, there what will be the difference in the level of menisci between the two arms?

1. 
   $2.1m$
2. 
   $3.8mm$
3. 
   $4.4mm$
4. 
   $10.6mm$

Q. If a $5\text{cm}$ long capillary tube with $0.2\text{mm}$ internal diameter open at both ends is slightly dipped in water having surface tension $75\text{dyne/cm}$. What will be the rise of water in capillary $($Take $g=1000\text{cm}/s^2$$)$

1. $15\text{cm}$
2. $5\text{cm}$
3. $10\text{cm}$
4. $20\text{cm}$

Q. A vessel, whose bottom has round holes with diameter $0.1\text{mm}$, is filled with water. The maximum height (in $\text{cm}$) up to which water can be filled without leakage is
(Take Surface Tension due to water as $75\frac{\text{dyne}}{\text{cm}},$acceleration due to gravity $g=1000\frac{\text{cm}}{{\text{s}}^2}$)

Q. If the length of a tube is less and cannot accommodate the maximum rise of liquid, then

1. Liquid will form a fountain
2. Liquid will not rise
3. The meniscus will adjust itself so that the water does not spill
4. None of the above

Q.

When a capillary is dipped in water, water rises to a height h. If the length of the capillary is made less than h, then

1. The water will come out

2. The water will not come out

3. The water will not rise

4. The water will rise but less than height of capillary

Q.

By inserting a capillary tube upto a depth l in water, the water rises to a height h. If the lower end of the capillary is closed inside water and the capillary is taken out and closed end opened, to what height the water will remain in the tube(l>h)

1. Zero

2. l+h

3. 2h

4. h

Q. Water rises up in a glass capillary up to a height of $9.0cm$, while mercury falls down by $3.4cm$ in the same capillary. Assume angles of contact for water glass and mercury glass $0^0$ and ${135}^0$ respectively. Determine the ratio of surface tension of mercury and water ($cos{135}^0=-0.71$)

Q. A capillary tube of radius R is immersed in water and water rises in it to a height H. Mass of water in the capillary tube is M, If the radius of the tube is doubled mass of water that will rise in capillary tube water be

1. 2M
2. M
3. $\frac{M}{2}$
4. 4M

Q. In a capillary rise experiment, the water level rises to a height of $5\text{cm}$. If the same capillary tube is placed in water such that only $3\text{cm}$ of the tube projects outside the water level, then:

1. water will begin to overflow through the capillary
2. angle of contact decreases
3. angle of contact increases
4. the meniscus completely vanishes

Q. Pressure at a point in a liquid is inversely proportional to the height of the liquid column.

1. True
2. False

Q. Consider the following statements regarding the experiment to determine the surface tension of water by capillary rise method
$1$. Capillary tube should be clean and liquid should be free from dirt and grease
$2$. Distilled water should be avoided
Choose the correct option

1. Only $1$ is correct
2. Only $2$ is correct
3. Both $1$ and $2$ are correct
4. Neither $1$ and $2$ are correct

Q. Two capillary tubes of same diameter are put vertically one each in two liquids whose relative densities are $0.8$ and $0.6$ and surface tensions are $60and50dyne/cm$ respectively. Ratio of heights of liquids in the two tubes $h_1/h_2$ is____

1. $\frac{10}{9}$
2. $\frac{3}{10}$
3. $\frac{10}{3}$
4. $\frac{9}{10}$

Q. Every liquid at rest exerts equal _______ in all directions at a point inside the liquid.

1. force
2. pressure
3. temperature
4. weight

Q. A long capillary tube of radius $1mm$, open at both ends is filled with water and placed vertically. What will be the height of water column left in the capillary ? (Surface tension of water is $73.5\times {10}^{-3}N.m^{-1}$)

1. $0.3cm$
2. $0.03cm$
3. $3cm$
4. $6cm$

Q. Water rises to a height of $10cm$ in a capillary tube and mercury falls to a depth of $3.42cm$ in the same capillary tube. If the density of mercury is $13.6g/c.c.$ and the angles of contact for mercury and water are ${135}^{\circ }$ and $0^{\circ }$, respectively, the ratio of surface tension for water and mercury is

1. $1:0.15$
2. $1:3$
3. $1:6.5$
4. $1.5:1$

Q. The lower end of a capillary tube is immersed in mercury. The level of mercury in the tube is found to be $2$cm below the outer level. If the same tube is immersed in water, up to what height will the water rise in the capillary?

Q. A capillary of the shape as shown is dipped in a liquid. Contact angle betweeen the liquid and the capillary is and effect of liquid inside the meniscus is to be neglected. $T$ is surface tension of the liquid. $r$ is radius of the meniscus, $g$ is acceleration due to gravity and p is density of the liquid then height $h$ is

1. greater than $\frac{2T}{\text{rpg}}$
2. Equal to $\frac{2T}{\text{rpg}}$
3. Less than $\frac{2T}{\text{rpg}}$
4. of any value depending upon actual values

Q. A capillary tube is attached horizontally to a constant pressure head arrangement. If the radius of the capillary tube is increased by $10\%,$ then the rate of flow of the liquid shall change nearly by :

1. $+10\%$
2. $46\%$
3. $-10\%$
4. $-40\%$

Q. If a $10\text{cm}$ long capillary tube with $0.2\text{mm}$ internal diameter open at both ends is slightly dipped in water having surface tension $80\text{dyne/cm}$, then:
[$g=981{\text{g/cm}}^2$]

1. Height to which water level will rise will be $16.31\text{cm}$.
2. Height to which water level will rise will be equal to length of capillary.
3. Radius of curvature of meniscus will be $0.163\text{mm}$.
4. Radius of curvature of meniscus will be $0.0163\text{mm}$.