91Ó°ÊÓ

The figure shows the points where we have to find the gauge pressure.

Using the concept of gauge pressure, we can see that the pressure value is proportional to the depth measured from the outer surface of the water.

Formula:

The gauge pressure at a depth on a body in downward direction, $P_g=\mathrm{ÒÏ}gh$ (i)

Gauge pressure is measured from the surface of the liquid.

We are measuring the gauge pressure from the surface of the tea spout as a reference level.

Thus, gauge pressure at each point is given using equation (i) as follows:

At point a:

$P_a=0$

At point d:

$P_d=0$

At point b:

Here, depth is downward.

Thus, the value of the pressure is given as:

$P_b=\mathrm{ÒÏ}gh$

At point c:

Here depth is measured upward. Hence,

$P_c=-\mathrm{ÒÏ}gh$

Therefore, the rank according to the gauge pressure in the water is$P_c<P_a=P_d<P_b.$