IDEAS TO DROP,BUBBLES AND EXCESS OF PRESSURE ACROSS A CURVED SURFACE AND DERIVATION OF CAPILLARY RISE.

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1. Will capillary rise occur and if it occurs what will be capillary rise if glass capillarity tube is immersed in water and experiment is carried out by astronauts in space. *

1 point

Capillarity rise will not occur

Capillarity rise will occur infinitely and will come out in form of fountain

Capillarity rise will occur finitely and will be the whole length of tube

None of the mentioned

2. Calculate the magnitude of capillary effect in millimeters in a glass tube of 7mm diameter, when immersed in mercury. The temperature of the liquid is 25℃ and the values of surface tension of mercury at 25℃ is 0.51 N/m. The angle of contact for mercury is 130°. *

1 point

140

230

220

240

3. Determine the minimum size of glass tube that can be used to measure water level if the capillary rise in the tube is restricted to 5mm. Consider surface tension of water in contact with air as 0.073 N/m *

1 point

5.95mm

11.9mm

2.97mm

4.46mm

4. Find the capillarity rise or fall if a capillary tube of diameter .03m is immersed in hypothetical fluid with specific gravity 6.5, surface tension 0.25 N/m and angle of contact 147°. *

1 point

0.44mm fall

0.88mm fall

0.44mm rise

0.88mm rise

5. The surface tension of fluid in contact with air at 25℃ is 0.51 N/m. The pressure inside a droplet is to be 0.05 N/cm2 greater than outside pressure. Determine the diameter of the droplet of water. *

1 point

4.08mm

8.16mm

2.04mm

None of the mentioned

6. Capillarity fall is reduced if we take the apparatus (capillary tube immersed in fluid having acute angle of contact) considerable distance inside the earth( i.e below the earth crust). *

1 point

7. For liquid fluids will capillarity rise (or fall) increase or decrease with rise in temperature. *

1 point

8. For a liquid-gas interface, the convex side has a higher pressure than the concave side. *

1 point

9 .Which of the following is correct regarding the formation and collapse of vapor bubbles in a liquid? *

1 point

Vapor bubbles are formed when the fluid pressure goes above the vapor pressure and collapses when the fluid pressure goes above the bubble pressure

Vapor bubbles are formed when the fluid pressure goes above the vapor pressure and collapses when the fluid pressure goes below the bubble pressure

Vapor bubbles are formed when the fluid pressure drops below the vapor pressure and collapses when the fluid pressure goes below the bubble pressure

Vapor bubbles are formed when the fluid pressure drops below the vapor pressure and collapses when the fluid pressure goes above the bubble pressure

10. A soap film is trapped between a frame and a wire of length 10 cm as shown in below figure then if the surface tension is given as 0.0049 N/m, what will be the value of m (in mg) such that the wire remains in equilibrium? *

1 point

0.1

100

11. A liquid jet of 5 cm diameter has a pressure difference of N/m2. (Take surface tension as 0.075 N/m) *

1 point

1.5

12. The ratio of the surface tension S and density ρ of liquid 1 and 2 are 1:2 and 1:4 respectively. Equal amount of the two liquids is poured into two identical tubes. what will be the ratio of the rise in the liquid level in the two tubes? (Assume the angle of contact to be same)

1 point

2:1

1:2

1:8

8:1

Clear selection

13. The rise in the level of a liquid in a tube is h. If half the amount is poured outside, what will be the new rise in liquid level? *

1 point

h/2

h/4

14. A water drop of diameter 1 cm breaks into 1000 similar droplets of same diameter. What will be the gain or loss in the surface energy? (Take surface tension as 0.075 N/m) *

1 point

gain of 0.424 mJ

gain of 0.212 mJ

loss of 0.212 mJ

loss of 0.424 mJ

15. Water rises through a height h in a capillary tube of internal radius (r). if T is the S.T. of water, then the pressure difference between the liquid level in the container and the lowest point of the concave meniscus is *

1 point

T/2r

2r/T

2T/r

r/4T

16. The angle of contact between a glass capillary tube of length 10 cm and a liquid is 90°. If the capillary tube is dipped vertically in the liquid, then the liquid *

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Will rise in the tube

Will get depressed in the tube

Will rise up to 10 cm in the tube and will over flow

Will neither rise nor fall in the tube

17. If soap bubbles of different radii are in communication with each other *

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Air flow from the larger bubble into the smaller one until the two bubbles are of equal size

The sizes of the bubbles remain unchanged.

Air flows from the smaller into the larger on and lager bubble grows at the expense of the smaller one

Air flows from the larger into the smaller one becomes equal to that of the larger one and the large one equal to that of the smaller one.

18. The rise of a liquid in a capillary tube does not depend upon *

1 point

Angle of contact

Density of the liquid

Radius of the capillary tube

Atmospheric pressure

19. The height of water in a capillary tube of radius 2 cm is 4 cm. what should be the radius of capillary, if the water rises to 8 cm in tube? *

1 point

1 cm

0.1 cm

2 cm

3 cm

20 . If a fluid of certain surface tension and diameter is used to create a soap bubble and a liquid jet. Which of the two, bubble or liquid jet, will have greater pressure difference on the inside and outside. *

1 point

Liquid jet

Soap bubble

Both will have same pressure differrence

None of the mentioned

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