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:
1. $\frac{79}{72}$

2. $\frac{19}{36}$

3. $\frac{39}{72}$

4. $\frac{79}{36}$

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:

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

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

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:
1. \(5.0\) g
2. \(10.0\) g
3. \(20.0\) g
4. \(2.5\) g

Which of the following diagrams does not represent a streamline flow?
 

1.		2.
3.		4.

With an increase in temperature, the viscosity of:
(a) gases decreases.
(b) liquids increases.
(c) gases increases.
(d) liquids decreases.
Which of the following options is/are correct?

The speed of flow past the lower surface of a wing of an aeroplane is 50 m/s. What speed of flow over the upper surface will give a dynamic lift of 1000 Pa? (Density of air = 1.3 kg/m³):
        
1. 25.55 m/s

2. 63.55 m/s

3. 13.25 m/s

4. 6.355 m/s