With an increase in temperature, the viscosity of liquid and gas, respectively will:

1.	increase and increase	2.	increase and decrease
3.	decrease and increase	4.	decrease and decrease

In a horizontal pipe of a non-uniform cross-section, water flows with a velocity of \(1~\text{ms}^{-1}\)${\mathrm{}}^{}$ at a point where the diameter of the pipe is \(20 ~\text{cm}.\) The velocity of water \((\text{ms}^{-1})\) at a point where the diameter of the pipe is \(5~\text{cm}\) is:
1. \(8\)
2. \(16\)
3. \(24\)
4. \(32\)

Two small spherical metal balls, having equal masses, are made from materials of densities \(\rho_1\) and \(\rho_2\) such that ${\rho }_1=8{\rho }_2$ and having radii of \(1\) mm and \(2\) mm, respectively. They are made to fall vertically (from rest) in a viscous medium whose coefficient of viscosity equals $\eta$ and whose density is \(0.1\)${\rho }_2$. The ratio of their terminal velocities would be:

A capillary tube of radius \(r\) is immersed in water and water rises in it to a height \(h.\) The mass of the water in the capillary is \(5\) g. Another capillary tube of radius \(2r\) is immersed in water. The mass of water that will rise in this tube is:

The wettability of a surface by a liquid depends primarily on:

Water rises to height h in a capillary tube. If the length of the capillary tube above the surface of water is made less than h, then:

A tank has an orifice near its bottom. The volume of the liquid flowing per second out of the orifice does not depend upon:

The speed of flow past the lower surface of a wing of an airplane is \(50~\text{m/s}.\) What speed of flow over the upper surface will give a dynamic lift of \(1000~\text{Pa}?\) 
(density of air \(1.3~\text{kg/m}^3\) )
                 
1. \(25.55~\text{m/s}\)
2. \(63.55~\text{m/s}\)
3. \(13.25~\text{m/s}\)
4. \(6.35~\text{m/s}\)

Small droplets of liquid are usually more spherical in shape than the larger drops of the same liquid because:

The velocity of a small ball of mass m and density $\mathrm{\rho }$ when dropped in a container filled with glycerin of density $\sigma$ becomes constant after sometime. The viscous force acting on the ball in the final stage is:-

1. $\mathrm{mg}\left(\frac{\mathrm{\sigma }}{\mathrm{\rho }}\right)$

2. $\mathrm{mg}\left(1+\frac{\mathrm{\sigma }}{\mathrm{\rho }}\right)$

3. $\mathrm{mg}\left(1-\frac{\mathrm{\sigma }}{\mathrm{\rho }}\right)$

4. mg