A satellite revolves round the earth. Air pressure inside the satellite is maintained at 76 cm of mercury. What will be the height of mercury column in a barometer tube 1 m long placed in the satellite?
The height in the mercury column increases due to the pressure. The atmospheric pressure on the free surface of the barometer is balanced by the weight of the liquid. In free space, there is no gravity to balance and hence the mercury will rise to the full length of 1m.