The excess pressure due to surface tension in a spherical liquid drop of radius r is directly proportional to

(a) r                                 (b) ${\mathrm{r}}^{2}$

(c) ${\mathrm{r}}^{-1}$                               (d) ${\mathrm{r}}^{-2}$

Concept Questions :-

Surface tension
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A long cylindrical glass vessel has a small hole of radius 'r' at its bottom. The depth to which the vessel can be lowered vertically in the deep water bath (surface tension T) without any water entering inside is

(a) $4\mathrm{T}/\mathrm{r\rho g}$                   (b) $3\mathrm{T}/\mathrm{r\rho g}$

(c) $2\mathrm{T}/\mathrm{r\rho g}$                   (d) $\mathrm{T}/\mathrm{r\rho g}$

Concept Questions :-

Capillary rise
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Difficulty Level:

The excess of pressure inside a soap bubble than that of the outer pressure is

(a) $\frac{2\mathrm{T}}{\mathrm{r}}$                       (b) $\frac{4\mathrm{T}}{\mathrm{r}}$

(c) $\frac{\mathrm{T}}{2\mathrm{r}}$                         (d) $\frac{\mathrm{T}}{\mathrm{r}}$

Concept Questions :-

Surface tension
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

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

(a) 100 dyne/cm                              (b) 68.66 dyne/cm
(c) 137 dyne/cm                              (d) 150 dyne/cm

Concept Questions :-

Surface tension
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Pressure inside two soap bubbles are 1.01 and 1.02 atmospheres. Ratio between their volumes is

(a) 102 : 101                             (b) $\left(102{\right)}^{3}:\left(101{\right)}^{3}$
(c) 8 : 1                                     (d) 2 : 1

Concept Questions :-

Surface tension
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The radii of two soap bubbles are ${\mathrm{r}}_{1}$ and ${\mathrm{r}}_{2}$ . In isothermal conditions, two meet together in vaccum. Then the radius of the resultant bubble is given by

(a) $\mathrm{R}=\left({\mathrm{r}}_{1}+{\mathrm{r}}_{2}\right)/2$                    (b) $\mathrm{R}={\mathrm{r}}_{1}\left({\mathrm{r}}_{1}{\mathrm{r}}_{2}+{\mathrm{r}}_{2}\right)$

(c) ${\mathrm{R}}^{2}={\mathrm{r}}_{1}^{2}+{\mathrm{r}}_{2}^{2}$                         (d) $\mathrm{R}={\mathrm{r}}_{1}+{\mathrm{r}}_{2}$

Concept Questions :-

Surface tension
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

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 column of water height H, then the depth of lake is

(a) H                                  (b) 2H
(c) 7H                                (d) 8H

Concept Questions :-

Pressure
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Difficulty Level:

Excess pressure of one soap bubble is four times more than the other. Then the ratio of volume of first bubble to another one is
(a) 1 : 64                    (b) 1 : 4
(c) 64 : 1                    (d) 1 : 2

Concept Questions :-

Surface tension
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

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

(a) More in the big drop

(b) More in the small drop

(c) Equal in both drops

(d) There is no excess pressure inside the drops

Concept Questions :-

Surface tension
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

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

(a) 10m                 (b) 20m
(c) 60m                 (d) 30m

Concept Questions :-

Pressure