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

The area of cross-section of the wider tube shown in the figure is $800$ ${\mathrm{cm}}^2.$ If a mass of 12 kg is placed on the massless piston, then the difference in heights h of the levels of water in the two tubes will be:

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

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:

A vertical \(\mathrm{U}\)-tube of uniform inner cross-section contains mercury in both its arms. A glycerin (density\(=1.3\) g/cm³) column of length \(10\) cm is introduced into one of its arms. Oil of density \(0.8\) g/cm³  is poured into the other arm until the upper surfaces of the oil and glycerin are at the same horizontal level. The length of the oil column is:
(density of mercury \(=13.6\) g/cm³)
                       
1. \(10.4\) cm
2. \(8.2\) cm
3. \(7.2\) cm
4. \(9.6\) cm

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

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: