difference between stress and pressure

In this article we are going to see Stress, Pressure, difference between stress and pressure and many more. Stress and pressure are two words that are frequently interchanged. Pressure is defined as the amount of force applied per unit area. Stress, on the other hand, is the amount of force exerted per unit area that a material experiences. The distinction between stress and pressure might assist us in better comprehending the fundamentals and understanding their parallels.

JEE Main 2025: Physics Formula | Study Materials | High Scoring Topics | Preparation Guide

JEE Main 2025: Syllabus | Sample Papers | Mock Tests | PYQs | Study Plan 100 Days

NEET 2025: Syllabus | High Scoring Topics | PYQs

This Story also Contains

What is the definition of stress?
What is the Definition of Pressure?
Difference between stress and pressure

What is the definition of stress?

The object deforms when the deforming force is given to it.

An opposing force will be generated inside the item in order to restore the thing to its previous shape and size. This restoring force will have the same magnitude as the applied deforming force but will be in the opposite direction. Stress is the measurement of the restoring force created per unit area of the material. As a result, stress is defined as "the material's restoring force per unit area." It's a tensor quantity.

The Greek letter is used to represent it. Pascal or N/m2 are the units of measurement. – is a mathematical expression. σ=F/A Where, The restoring force is expressed in Newtons or N. A is the cross-sectional area in metres squared. σ is the stress, expressed in N/m2 or Pa.

Also read -

Types of Stress

In physics, there are various types of stress, however they are primarily divided into two types: normal stress and tangential or shearing stress. The next sections go over some of the different types of stress.

Normal Stress:

Normal stress is the one in which the direction of the applied force is normal to the cross-sectional area of the body, stress is said to be normal stress. The stress will be normal as the length of the wire or the volume of the body changes. Normal stress is further divided into two types based on the force dimension. Longitudinal stress Bulk stress, also known as volumetric stress

Longitudinal Stress:

Consider the shape of a cylinder.

When two cross-sectional sections of the cylinder are exposed to equal and opposite forces, it undergoes stress. The stress is called a longitudinal stress.
Deforming Force / Area of Cross-section = F/A = Longitudinal Stress

The Longitudinal Stress stretches or compresses the thing along its whole length.

As a result, based on the direction of deforming force, it can be further categorised into two types:

Tensile stress

Compressive stress

Tensile Stress

Tensile stress is defined as a stress that occurs when a deforming force or applied force causes an increase in the length of an object.

For example, a rod or wire can be stretched by drawing it at both ends with equal and opposite forces (outwards).

Compressive Stress

When a deforming force or applied force causes an object's length to shrink, the resulting tension is known as compressive stress.

When a rod or wire is compressed/squeezed by pulling it inwards with equal and opposite forces at both ends, for example.

Bulk Stress or Volume Stress

When a deforming force or applied force acts on an object in all dimensions, causing a change in volume, this is referred to as volumetric stress or bulk stress.

Volume stress occurs when the volume of a body changes as a result of a deforming force.

Shearing Stress or Tangential Stress

When the applied force is parallel to the cross-sectional area of the object then the stress is called shearing stress or tangential stress. The body's shape changes as a result of this.

Related Topics Link,

JEE Main Highest Scoring Chapters & Topics

Just Study 40% Syllabus and Score upto 100%

Download E-book

What is the Definition of Pressure?

Because the pressure is thrust per unit area, it is proportional to thrust directly and inversely to area.
Pounds per square inch, Newtons per square metre, and Pascals are the units of pressure.

Other units for expressing pressure include atmosphere, bar, torr, and metres sea water.
The SI unit of pressure is the Pascal, which is a derived unit.

The equation that is used to express pressure is as follows:

P=F/A

Where,

P stands for pressure.

The force acting per unit area is denoted by F.

The unit area is A.

The fascinating aspect of pressure is that it is a scalar quantity, meaning that it has simply magnitude and no direction.

The value of pressure can be either positive or negative.

The following are some types of pressure that you may encounter on a daily basis:

The vacuum cleaner's operation is an illustration of pressure.

The vacuum's fan generates a low-pressure zone inside the vacuum, making it simple to suck dust particles in.

Another example of pressure is cutting with a knife.

Although the knife's exposed surface is minimal, the pressure is sufficient to cut the veggies and fruits.

NCERT Physics Notes :

Different Types Of Pressure

Pressure classified as follows:-

Absolute Pressure
Gauge Pressure
Differential Pressure
Vacuum pressure or sealed pressure

Absolute Pressure

It's a sort of pressure that uses a vacuum or an airless environment as a reference point. Because atmospheric pressure differences alter as the location changes, this sort of pressure varies as well. It eliminates the reference to variable ambient pressure and depends on a defined pressure range for reference by employing a device like an absolute pressure sensor.

Gauge Pressure

The difference between absolute and atmospheric pressure is known as gauge pressure. Relative pressure is another name for gauge pressure. At sea level, the observed pressure is compared to the standard atmospheric pressure. The vent on pressure sensors used to measure gauge pressure allows the instrument to use ambient pressure as a reference point. Both positive and negative values can be assessed. Overpressure is the term for positive values. Underpressure or partial vacuum occurs when the gauge pressure measurement is negative.

Differential Pressure

Differential pressure is the difference between two pressures and is a sort of gauge pressure. It aids in determining the pressure difference between two places. Flow and level measurement applications use differential pressure. The suffix "d" is used to represent differential pressure.

Sealed Pressure

The vacuum is defined as a space with no absolute pressure. Perfect vacuum is difficult to obtain in practise and only exists as a theoretical value. A vacuum is generated when the pressure is lower than the atmospheric pressure. In practise, the vacuum will only be attained partially, which is referred to as partial vacuum.

A high vacuum indicates a very low absolute pressure. The pressure is measured in a sealed chamber that is kept at atmospheric pressure. The sealed sensor is used to measure the sealed pressure and is made out of an airtight sensing element that prevents further pressure changes owing to changes in ambient conditions. Pressure transducers are protected from damage by sealed pressure. Now lets talk about stress vs pressure in which we are going to see the stress and pressure difference

Also read :

Stress	Pressure
Stress is defined as the internal resistive force to deformation per unit area.	Pressure is defined as the amount of force applied per unit area.
(strain) / (Young's modulus) can be used to represent stress.	Pressure can be expressed mathematically as (force) / (area)
Stress is a material characteristic.	Pressure is a distinctive feature of thermodynamics or physics.
Stress can be viewed as either a beneficial or negative force.	The force of pressure is always a positive force.
There is no stress measurement instrument (not a measurable quantity). Strain or elongation are used to calculate stress.	Pressure gauges, manometers, and other pressure measuring equipment or instruments are used to physically measure (measure) the pressure.
Tensile, compressive, and shear stress are all possible.	Compressive pressure is constantly present.
The level of tension at a different place in a different direction varies.	The magnitude of pressure at a location remains constant in all directions.
The stress fluctuates as the surface area changes.	The pressure is unaffected by the size of the contact surface. It remains constant and does not change while the surface area changes.
Internal stress develops.	External pressure is exerted

Also check-

Frequently Asked Questions (FAQs)

1. What is the definition of stress?

Stress is defined as the amount of restoring force per unit of area.

2. What is the stress unit?

The unit of stress is the pascal (N/m2).

3. What effect does deforming force have?

The deforming force might alter the object's shape, volume, or size.

4. In the case of shearing stress, what is the direction of the deforming force?

The deforming force is parallel to the cross-sectional area.

5. What is the difference between stress and pressure in physics?

Stress is defined as the internal resistive force to deformation per unit area.	Pressure is defined as the amount of force applied per unit area.
(strain) / (Young's modulus) can be used to represent stress.	Pressure can be expressed mathematically as (force) / (area)
Stress is a material characteristic.	Pressure is a distinctive feature of thermodynamics or physics.
Stress can be viewed as either a beneficial or negative force.	The force of pressure is always a positive force.
There is no stress measurement instrument (not a measurable quantity). Strain or elongation are used to calculate stress.	Pressure gauges, manometers, and other pressure measuring equipment or instruments are used to physically measure (measure) the pressure.
Tensile, compressive, and shear stress are all possible.	Compressive pressure is constantly present.