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

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

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

Water flows through a horizontal tube as shown in figure. If the difference in heights of water column in vertical tubes is 80 cm and the area of cross-section at A and B are 5 cm² and 3 cm² respectively, then the rate of flow of water at A( in cc/sec) is:-

[$Take$ $g$ $=10$ $m/s^2$]

1. $15\times {10}^2$

2. $15\times {10}^3$

3. 150

4. None of these

Two soap bubbles are connected by a tube as shown in the figure. Which of the following statement is true?
                                  

Water flows through a frictionless tube with a varying cross-section as shown in the figure. Variation of pressure P at point x along the axis is roughly given by:

1.		2.
3.		4.

A water tank is kept at a height H above the ground and the tank contains depth H of water as shown. Find the maximum possible range of water current, if there exists a small hole on the sidewall of the tank.
          

The diameter of a syringe is 4 mm and the diameter of its nozzle (opening) is 1 mm. The syringe is placed on the table horizontally at a height of 1.25 m. If the piston is moved at a speed of 0.5 m/s, then considering the liquid in the syringe to be ideal, the horizontal range of liquid is: (g = 10 m/${\mathrm{s}}^2$)
1. 4 m
2. 8 m
3. 0.4 m
4. 0.2 m

An iron sphere is dropped into a viscous liquid. Which of the following represents its acceleration (a) versus time (t) graph?

1.		2.
3.		4.