Question 2 :
The principle of fluid pressure that is used in hydraulic brakes or lifts is that.<br>

Question 3 :
Two spheres of radii ${r}_{1}$ and ${r}_{2}$ (${r}_{1}&gt; {r}_{2})$ is dropped through a tube full of glycerine. Their terminal velocities ${v}_{1}$ and ${v}_{2}$ are calculated in the experiment. Which of the following is true?

Question 4 :
If the surface tension of water is $0.06N/m$, then the capillary rise in a tube of a diameter $1mm$ is :($\theta={0}^{o}$)

Question 5 :
A drop of water of radius r is falling through the&#160;air of coefficient of viscosity $\eta&#160;$ with a constant&#160;velocity of v. The resultant force on the drop is:

Question 6 :
The excess pressure inside a small air bubble&#160;of radius $0.05 mm$ in water of surface tension $70\ dyne- cm^{-1}$ is $Pa$:

Question 7 :
A ball rises to the surface of a liquid with constant velocity. The density of the liquid is four time the density of the material of the ball. the frictional force of the liquid on the rising ball is greater than the weight of the ball by a factor of<br>

Question 8 :
A marble of mass $x$ and diameter $2r$ is gently released in tall cylinder containing honey. If the marble displace mass $y(&lt; x)$ of the liquid, then the terminal velocity is proportional to<br>

Question 9 :
The amount of work done is blowing a soap bubble such that its diameter increases from $d$ to $D$ is ($S =$ surface tension of the solution) :

Question 10 :
A small hollow sphere, which has a small hole in it, is immersed in water to a depth of 0.5 m before any drop penetrates into it. If surface tension for water is 0.073 N/m, the radius of the hole is :[Assume pressure inside the sphere to be atmospheric pressure]

Question 11 :
The pressure at the bottom of a tank of water is $3P$ where $P$ is the atmospheric pressure. If the water is drawn out till the level of water is lowered by one fifth, the pressure at the bottom of the tank will now be:<br/>

Question 12 :
A capillary tube of radius $r$ is immersed in water and water rises to a height of $h$. Mass of water in the capillary tube is $5\times 10^{-3}kg$. The same capillary tube is now immersed in a liquid whose surface tension is $\sqrt{2}$ times the surface tension of water. The angle of contact between the capillary tube and this liquid is $45^o$. The mass of liquid which rises into the capillary tube now is (in kg):

Question 13 :
A tank in filled with water of density $10^3 kg/m^3$ and oil of density $0.9\times 10^3 kg/m^3$. The height of water layer is $1 m$ and that of the oil layer is $4 m$. The velocity of efflux from an opening in the bottom of the tank is

Question 14 :
The surface tension of a liquid is $5 N/m$. If a film of this liquid is held on a ring of area $0.02 &#160;{m}^{2} $, its surface energy is about :

Question 15 :
If the excess pressure inside a soap bubble of radius ${ r }_{ 1 }$ in air is equal to the excess pressure inside air bubble of radius ${ r }_{ 2 }$ inside the soap solution, then ${ r }_{ 1 }:{ r }_{ 2 }$ is