Question

A water manometer is connected to a gas supply.
There is a gas leak and the pressure of the gas supply falls. What happens to the water level at P and what happens to the water level at Q?

• A. Water level at P- falls, Water level at Q- falls
• B. Water level ay P- falls, Water level at Q- rises
• C. Water level at P- rises, Water level at Q- falls
• D. Water level at P- rises, Water level at Q- rises

Answer 1

The correct option is C Water level at P- rises, Water level at Q- falls

The net difference in height of column of water is due to the excess pressure of gas .

So, if the pressure of gas get decreases then the the difference between the water in column P and column Q decreases .

Therefore the water level at P rises and water level at Q falls .