The density of ice is x gm/cc and that of water is y gm/cc. What is the change in volume in cc, when m gm of ice melts?

1.  M(y-x)

2.  (y-x)/m

3.  mxy(x-y)

4.  m(1/y-1/x)

A body weighs 160 g in air, 130 g in water and 136 g in oil. The specific gravity of oil is
1. 0.2 

2. 0.6

3. 0.7 

4. 0.8

A soap bubble, having a radius of \(1~\text{mm}\), is blown from a detergent solution having a surface tension of\(2.5\times 10^{-2}~\text{N/m}\)$$. The pressure inside the bubble equals at a point \(Z_0\) below the free surface of the water in a container. Taking \(g = 10~\text{m/s}^{2}\)${\mathrm{}}^{}$, the density of water \(= 10^{3}~\text{kg/m}^3\)${\mathrm{}}^{}$, the value of \(Z_0\) is:

A small hole of an area of cross-section \(2~\text{mm}^2\) is present near the bottom of a fully filled open tank of height \(2~\text{m}\). Taking \(g = 10~\text{m/s}^2\)${\mathrm{}}^{}$, the rate of flow of water through the open hole would be nearly:
1. \(6.4\times10^{-6}~\text{m}^{3}/\text{s}\)
2. \(12.6\times10^{-6}~\text{m}^{3}/\text{s}\)
3. \(8.9\times10^{-6}~\text{m}^{3}/\text{s}\)
4. \(2.23\times10^{-6}~\text{m}^{3}/\text{s}\)

A small sphere of radius r falls from rest in a viscous liquid. As a result, heat is produced due to the viscous force. The rate of production of heat when the sphere attains its terminal velocity is proportional to

1. ${\mathrm{r}}^3$

2. ${\mathrm{r}}^2$

3. ${\mathrm{r}}^4$

4. ${\mathrm{r}}^5$

Three liquids of densities \(d,\) \(2d\) and \(3d\) are mixed in equal proportions of weights. The relative density of the mixture is: 

By sucking through a straw, a student can reduce the pressure in his lungs to 750 mm of Hg $(\mathrm{density} = 13.6 \mathrm{gm}/{\mathrm{cm}}^3).$ Using the straw, he can drink water from a glass up to a maximum depth of :

1.  10 cm 

2.  75 cm

3.  13.6 cm 

4.  1.36 cm

If the terminal speed of a sphere of gold $(\mathrm{density} = 19.5 \mathrm{kg}/{\mathrm{m}}^3)$ is 0.2 m/s in a viscous liquid $(\mathrm{density} = 1.5 \mathrm{kg}/{\mathrm{m}}^3),$ find the terminal speed of a sphere of silver $(\mathrm{density} = 10.5 \mathrm{kg}/{\mathrm{m}}^3)$ of the same size in the same liquid

1.  0.4 m/s 

2.  0.133 m/s

3.  0.1 m/s 

4.  0.2 m/s

$\mathrm{A} \mathrm{spherical} \mathrm{solid} \mathrm{ball} \mathrm{of} \mathrm{volume} \mathrm{V} \mathrm{is} \mathrm{made} \mathrm{of} \mathrm{a} \mathrm{material} \mathrm{of} \mathrm{density} {\mathrm{\rho }}_1. \mathrm{It} \mathrm{is} \mathrm{falling} \mathrm{through} \mathrm{a} \mathrm{liquid} \mathrm{of} \mathrm{density} {\mathrm{\rho }}_1 ({\mathrm{\rho }}_2 < {\mathrm{\rho }}_1). \mathrm{Assume} \mathrm{that} \mathrm{the}$
$\mathrm{liquid} \mathrm{applies} \mathrm{a} \mathrm{viscous} \mathrm{force} \mathrm{on} \mathrm{the} \mathrm{ball} \mathrm{that} \mathrm{is} \mathrm{proportional} \mathrm{to} \mathrm{the} \mathrm{square} \mathrm{of} \mathrm{its} \mathrm{speed} \mathrm{v}, \mathrm{i}.\mathrm{e}., {\mathrm{F}}_{\mathrm{viscous}} = –{\mathrm{kv}}^2 (\mathrm{k} > 0). \mathrm{The} \mathrm{terminal}$
$\mathrm{speed} \mathrm{of} \mathrm{the} \mathrm{ball} \mathrm{is}$

1.  $\sqrt{\frac{\mathrm{Vg}\left({\mathrm{\rho }}_1 - {\mathrm{\rho }}_2\right)}{\mathrm{k}}}$

2.  $\frac{{\mathrm{Vg\rho }}_1}{\mathrm{k}}$

3.  $\sqrt{\frac{{\mathrm{Vg\rho }}_1}{\mathrm{k}}}$

4.  $\frac{\mathrm{Vg}\left({\mathrm{\rho }}_1 - {\mathrm{\rho }}_2\right)}{\mathrm{k}}$