Three liquids of densities \(d,\) \(2d\) and \(3d\) are mixed in equal proportions of weights. The relative density of the mixture is: 

1.	\(11d \over 7\)	2.	\(18d \over 11\)
3.	\(13d \over 9\)	4.	\(23d \over 18\)

The pressure of water in a water pipe when tap is opened and closed are respectively \(3\times10^5\) Nm^–2 and \(3.5\times10^5\) Nm^–2. With open tap, the velocity of water flowing is:
              
1. \(10\) ms^–1                           
2. \(5\) ms^–1
3. \(20\) ms^–1       
4. \(15\) ms^–1

A small hole of an area of cross-section \(2~\text{mm}^2\) is present near the bottom of a fully filled open tank of height \(2~\text{m}\). Taking \(g = 10~\text{m/s}^2\)${\mathrm{}}^{}$, the rate of flow of water through the open hole would be nearly:
1. \(6.4\times10^{-6}~\text{m}^{3}/\text{s}\)
2. \(12.6\times10^{-6}~\text{m}^{3}/\text{s}\)
3. \(8.9\times10^{-6}~\text{m}^{3}/\text{s}\)
4. \(2.23\times10^{-6}~\text{m}^{3}/\text{s}\)

A small spherical solid ball is dropped in a viscous liquid. Its journey in the liquid is best described in the figure by:
                        

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:

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: