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:

 A body is just floating on the surface of a liquid. The density of the body is the same as that of the liquid. The body is slightly pushed down. What will happen to the body?

If two pieces of metal when immersed in a liquid have equal upthrust on them, then:

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 square plate of 0.1 m side moves parallel to a second plate with a velocity of 0.1 m/s, both plates being immersed in water. If the viscous force is 0.002 N and the coefficient of viscosity is 0.01 poise, then the distance between the plates in m 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: