Air is pushed into a soap bubble of radius r to double its radius. If the surface tension of the soap solution is S, the work done in the process is
1. 8 \(\pi\) r2 S
2. 12 \(\pi\) r2 S
3. 16 \(\pi\) r2 S
4. 24 \(\pi\) r2 S
If more air is pushed in a soap bubble, the pressure in it
1. decreases
2. increases
3. remains same
4. becomes zero
If two soap bubbles of different radii are connected by a tube,
1. | air flows from bigger bubble to the smaller bubble till the sizes become equal. |
2. | air flows from bigger bubble to the smaller bubble till the sizes are interchanged. |
3. | air flows from the smaller bubble to the bigger. |
4. | there is no flow of air. |
The figure shows a capillary tube of radius r dipped into water. If the atmospheric pressure is P0, the pressure at point A is pressure at point A is
1. \(P_{0}\)
2. \(P_{0}+\frac{2 S}{r}\)
3. \(P_{0}-\frac{2 S}{r}\)
4. \(P_{0}-\frac{4 S}{r}\)
The excess pressure inside a soap bubble is twice the excess pressure inside a second soap bubble. The volume of the first bubble is n times the volume of the second where n is
1. 4
2. 2
3. 1
4. 0.125
Which of the following graphs may represent the relation between the capillary rise h and the radius r of the capillary?
1.
2.
3.
4.
Water rises in a vertical capillary tube upto a length of 10 cm. If the tube is inclined at 45°, the length of water risen in the tube will be
1. 10 cm
2. 10\(\sqrt2\)cm
3. 10/\(\sqrt2\)cm
4. none of these
A 20 cm long capillary tube is dipped in water. The water rises up to 8 cm. If the entire arrangement is put in a freely falling elevator, the length of water column in the capillary tube will be
1. 8 cm
2. 6 cm
3. 10 cm
4. 20 cm
Viscosity is a property of:
1. liquids only
2. solids only
3. solids and liquids only
4. liquids and gases only
The force of viscosity is
1. electromagnetic
2. gravitational
3. nuclear
4. weak