Question

Why does the barometric height read less at Darjeeling than at Puri?

Answer 1

Hint: The barometric formula is used to calculate the change in air density with change in altitude.
Also there is a relation between pressure and altitude, $P = \rho gh$ which we are going to use in this solution for explanation.

Complete step by step solution:
We all know that Darjeeling is a hill station in the state of West Bengal and Puri is near the Bay of Bengal. So, Darjeeling is at an altitude far higher than Puri.
The pressure exerted by air in the atmosphere at the earth’s surface is maximum and reduces as the altitude increases. The explanation for this is that at sea level the density and volume of the atmosphere is highest and decreases with rising altitude. Also, the air molecules are less in number at a high altitude as compared to air molecules at low altitude.
Barometric height is used as a measurement to express the atmospheric pressure and air pressure retaining mercury in the container, so mercury height is used as a unit to reflect the atmospheric pressure.
$P = \rho gh$, where $P = $pressure, $\rho = $density of liquid, $g = $gravity and $h = $height. This expression is used to measure barometric pressure or height. We can compute the height by understanding the atmospheric pressure.

So, it can be concluded from above that the barometric height is less at Darjeeling than at Puri due to the air column mass which is less over Darjeeling than at Puri.

Note: While calculating barometer height it is important to note that we should not use mercury barometer as it is heavy and poisonous. An aneroid barometer can be used in place of mercury barometer.