The height of a mercury barometer is 75 cm at sea level and 50 cm at the top of a hill. The ratio of density of mercury to that of air is ${10}^4$. The height of the hill is:

1.	250 m	2.	2.5 km
3.	1.25 km	4.	750 m

The value of g at a place decreases by 2%. Then, the barometric height of mercury:

A barometer kept in a stationary elevator reads 76 cm. If the elevator starts accelerating up, the reading will be:

The following fig. shows the flow of liquid through a horizontal pipe. Three tubes A, B and C are connected to the pipe. The radii of the tubes A, B and C at the junction are respectively 2 cm, 1 cm and 2 cm. It can be said that the:

There is a hole in the bottom of a tank having water. If the total pressure at the bottom is 3 atm ($1$ $\mathrm{atm}={10}^5$ $\mathrm{N}/{\mathrm{m}}^2$), then the velocity of water flowing from the hole is:

A spherical ball of radius \(r\) is falling in a viscous fluid of viscosity \(\eta\) with a velocity \(v.\) The retarding viscous force acting on the spherical ball is:

The pans of a physical balance are in equilibrium. If Air is blown under the right hand pan then the right hand pan will:

A tank is filled with water up to a height \(\mathrm H.\) Water is allowed to come out of a hole \(\mathrm P\) in one of the walls at a depth \(\mathrm D\) below the surface of water. Express the horizontal distance \(\mathrm{x}\) in terms of \(\mathrm H\) and \(\mathrm {D}\text :\)
                    

1. $\mathrm{x}=\sqrt{\mathrm{D}(\mathrm{H}-\mathrm{D})}$

2. $\mathrm{x}=\sqrt{\frac{\mathrm{D}(\mathrm{H}-\mathrm{D})}{2}}$

3. $\mathrm{x}=2\sqrt{\mathrm{D}(\mathrm{H}-\mathrm{D})}$

4. $\mathrm{x}=4\sqrt{\mathrm{D}(\mathrm{H}-\mathrm{D})}$

If the excess pressure inside a soap bubble is balanced by an oil column of height of \(2\) mm, then the surface tension of the soap solution will be: (radius of the soap bubble, \(r=1\) cm and density of oil, \(d=0.8\) gm/cm³)
1. \(3.9\) N/m
2. $3.9\times {10}^{-2}$ $\mathrm{N}/\mathrm{m}$
3. $3.9\times {10}^{-3}$ $\mathrm{N}/\mathrm{m}$
4. \(3.9\) dyne/m

If the surface tension of water is 0.06 ${\mathrm{Nm}}^{-1}$, then the capillary rise in a tube of diameter 1 mm is: \((\theta = 0^{\circ})\)
1. 1.22 cm
2. 2.44 cm
3. 3.12 cm
4. 3.86 cm