The pressure of air in a soap bubble of 0.7cm diameter is 8 mm of water above the pressure outside. The surface tension of the soap solution is

(1) 100 dyne/cm

(2) 68.66 dyne/cm

(3) 137 dyne/cm

(4) 150 dyne/cm

The pressure inside two soap bubbles are 1.01 and 1.02 atmospheres. The ratio between their volumes is

(1) 102 : 101

(2) $(102{)}^3:(101{)}^3$

(3) 8 : 1

(4) 2 : 1

The radii of two soap bubbles are ${\mathrm{r}}_1$ and ${\mathrm{r}}_2$ . In isothermal conditions, two meet together in a vacuum. Then the radius of the resultant bubble is given by

(1) $\mathrm{R}=({\mathrm{r}}_1+{\mathrm{r}}_2)/2$

(2) $\mathrm{R}={\mathrm{r}}_1({\mathrm{r}}_1{\mathrm{r}}_2+{\mathrm{r}}_2)$

(3) ${\mathrm{R}}^2={\mathrm{r}}_1^2+{\mathrm{r}}_2^2$ 

(4) $\mathrm{R}={\mathrm{r}}_1+{\mathrm{r}}_2$

When a large bubble rises from the bottom of a lake to the surface, its radius doubles. If atmospheric pressure is equal to that of a column of water height H, then the depth of the lake is

(1) H

(2) 2H

(3) 7H

(4) 8H

The excess pressure of one soap bubble is four times more than the other. Then the ratio of the volume of the first bubble to another one is 

(1) 1 : 64

(2) 1 : 4

(3) 64 : 1

(4) 1 : 2

There are two liquid drops of different radii. The excess pressure inside over the outside is 

(1) More in the big drop

(2) More in the small drop

(3) Equal in both drops

(4) There is no excess pressure inside the drops

If pressure at half the depth of a lake is equal to 2/3 pressure at the bottom of the lake then what is the depth of the lake

(1) 10m

(2) 20m

(3) 60m

(4) 30m

In capillary tube, pressure below the curved surface of water will be 

(1) Equal to atmospheric

(2) Equal to upper side pressure

(3) More than upper side pressure

(4) Lesser than upper side pressure

Two soap bubbles have different radii but their surface tension is the same. Mark the correct statement

(1) Internal pressure of the smaller bubble is higher than the internal pressure of the larger bubble

(2) Pressure of the larger bubble is higher than the smaller bubble

(3) Both bubbles have the same internal pressure

(4) None of the above

Due to capillary action, a liquid will rise in a tube, if the angle of contact is 

(1) Acute

(2) Obtuse

(3) 90°

(4) Zero