The radius of a soap bubble is increased from R to 2 R. Work done in this process (T = surface tension) is: 

A cubical vessel of height 1 m is full of water. Find the work done in pumping out whole water.

1. 49 J

2. 490 J

3. 4900 J

4. 49000 J

The flow rate from a tap of diameter 1.25 cm is 3 lit/min. The coefficient of viscosity of water is ${10}^{-3}$ Pas. The nature of flow is :

1. Turbulent

2. Laminar

3. Neither laminar nor turbulent

4. data inadequate

Water flowing from a hose pipe fills a 15-liter container in one minute. The speed of water from the free opening of radius 1 cm is (in ms${}^{-1}$) :

1. 2.5

2. $\frac{\mathrm{\pi }}{2.5}$

3. $\frac{2.5}{\mathrm{\pi }}$

4. 5 $\mathrm{\pi }$

Work of 6.0 x 10${}^{-4}$ Joule is required to be done in increasing the size of a soap film from 10cm x 6cm to 10cm x 11cm. The surface tension of the film is :

1. 5 x 10${}^{-2}$ N/m

2. 6 x 10${}^{-2}$ N/m

3. 1.5 x 10${}^{-2}$ N/m

4. 1.2 x 10${}^{-1}$ N/m

When a cylindrical tube is dipped vertically into a liquid the angle of contact is 140^o. When the tube is dipped with an inclination of 40^o, the angle of contact is- 

1.  $100°$  

2.  $140°$

3.  $180°$

4.    $60°$

Two liquid drops have their diameters as 1 mm and 2 mm. The ratio of excess pressure in them is :

1.  1:2

2.  2:1

3.  4:1

4.  1:4

The rate of flowing of water from the orifice in a wall of a tank will be more if the orifice is:

1.  Near the bottom

2.  Near the upper end

3.  Exactly in the middle

4.  Does not depend upon the position of the orifice

Water flows through a frictionless duct with a cross-section varying as shown in the figure. Pressure p at points along the axis is represented by
         

1.		2.
3.		4.

In the figure below is shown the flow of liquid through a horizontal pipe. Three tubes A, B, and C are connected to the pipe. The radius of the pipe at A, B, and C is respectively 2 cm, 1 cm, and 2 cm. It can be said that the :

 

1. Height of the liquid in the tube A is maximum

2. Height of the liquid in the tubes A and B is the same

3. Height of the liquid in all the three tubes is the same

4. Height of the liquid in the tubes A and C is the same