An airplane of a total wing area of \(120\) ${\mathrm{m}}^2$ is in a level flight at some height. If the pressure difference between the upper and lower surface is \(2.5\) kPa, then the mass of the airplane is: (Take \(g=10\) ${\mathrm{ms}}^{-2}$)

1.	\(2\times10^3\) kg	2.	\(3\times10^4\) kg
3.	\(5\times10^4\) kg	4.	\(7\times10^4\) kg

A block weighs 5 N in air and 4.5 N in a liquid of specific gravity 0.5. Its weight in water will be:

1. 3.5 N

2. 4.0 N

3. 2.5 N

4. 3.0 N

A liquid is poured into three vessels of the same base area and equal heights as shown in the figure, then:
                                  

The relative velocity of two adjacent layers of a liquid is 6 cm/s and the perpendicular distance between layers is 0.1 mm. The velocity gradient for liquid (in per second) is:

A large open tank with a square hole of side \(0.1\) cm in the wall at a depth of \(0.2\) m from the top is completely filled with a liquid. The rate of flow of liquid (in ${\mathrm{cm}}^3$/s) through the hole will be: 

When a man sits on a boat of length 2 m and breadth 1 m floating on a lake, the boat sinks by 2 cm. The mass of the man is:

1. 25 kg

2. 40 kg

3. 60 kg

4. 80 kg

There are four cylindrical vessels identical in dimensions. If these are filled with equal masses of four different liquids P, Q, R, and S such that their densities are ${\mathrm{\rho }}_{\mathrm{p}}$ $>$ ${\mathrm{\rho }}_{\mathrm{Q}}$ $>$ ${\mathrm{\rho }}_{\mathrm{R}}$ $>$ ${\mathrm{\rho }}_{\mathrm{S}}$, then pressure at the base of vessel will be: 

A beaker full of water is placed on a spring balance. If we put our finger in water without touching the beaker, how will the reading of the balance change? [Take ${\mathrm{\rho }}_{\mathrm{finger}}$ $>$ ${\mathrm{\rho }}_{\mathrm{water}}$]
1. Increase
2. Decrease
3. Remain the same
4. Will be halved

If a capillary tube is partially dipped vertically into liquid and the levels of the liquid inside and outside are same, then the angle of contact is:

From the given diagram, the velocity \(v_3\) is: