# The Physics of Pressure

Note4Students

From UPSC perspective, the following things are important :

Prelims level: Pressure and its impacts

## Why in the News?

• Pressure is an indispensable part of life, often unnoticed but always present.
• It’s the interaction of microscopic particles with the macroscopic world, creating phenomena like air pressure.

## What is Pressure?

• Pressure is defined as the force exerted per unit area on a surface.
• For example, an apple weighing 100 g exerts a force of about 1 newton (N) on your hand and a pressure of approximately 500 Pa.
• Atmospheric pressure is around 100,000 Pa, equivalent to the pressure exerted by about 200 apples on your hand.

## (1) Measuring Blood Pressure:

• Blood pressure, measured in mm of mercury (mmHg), is an example of pressure in a different context.
• Blood pressure is measured using a sphygmomanometer, which balances the pressure in an arm cuff with the pressure of the blood in the arteries.
• The readings, such as 120/80 mmHg, represent the pressure during heartbeats (systolic) and between beats (diastolic).
• Mercury, being 15 times heavier than water, allows for portable blood-pressure machines.

## (2) Pressure Cookers:

• The whistle of a pressure cooker is a direct result of the increased pressure cooking the food efficiently.
• The pressure cooker exemplifies the practical application of pressure in cooking, making it an indispensable kitchen tool.

## PYQ:

[2021] In a pressure cooker, the temperature at which the food is cooked depends mainly upon which of the following?​

1. Area of the hole in the lid​

2. Temperature of the flame​

3. Weight of the lid​

Select the correct answer using the code given below.​

(a) 1 and 2 only ​

(b) 2 and 3 only​

(c) 1 and 3 only ​

(d) 1, 2 and 3​

Get an IAS/IPS ranker as your 1: 1 personal mentor for UPSC 2024

Attend Now

Subscribe
Notify of