Question

What is most nearly the gage pressure at point A in the tank of water ifh-2 m? h = 2 m (A) 12 P. (©) oks (D) 2017:

Answer 1

First of all, the word 'gage' is a misprint.It must be 'gauge'.

Atmospheric presuure:It is the pressure exerted by atmospheric air normally (perpendicularly) on any suface with which it is in contact.

Absolute pressure: It is the pressure measured above or below complete vacuum or absolute zero pressure.

Gauge pressure:It is measured above or below atmospheric pressure.

Pressure on the surface of static liquid is atmospheric pressure or zero guage pressure.

As one move down the surface of a liquid (in static condition), gauge pressure increases as follows:-

P=γd, where γ=specific weight(weight density)=weight per unit volume

d=depth of concerned point below the surface of liquid

In case of water , γ=9.8kN/m3

Pressure at a point 2m below surface of water is given by:-

P=γd

=9.8kN/m3 * 2m

=19.6kN/m2

There is no such option and the most near answer in the options is 20kN/m2

Hence,the answer is 20kN/m2 and the correct option is option D