# What is the Difference between Stress and Strain in Physics

## Difference between Stress & Strain

When a body is made to change its length, volume or shape by the application of an external force, the opposing force per unit area is called Stress.

Formula:

Stress = Force / Area

o = F/A (Here o represents (Rho) do not write in your examination paper)

Units:

– S.I or M.K.S System – N/m2 or Pascal (Pa)

– C.G.S system – Dyne/cm2

– F.P.S or BE System – lb/ft2 and lb/in2

(Here 2 in all above systems shows square)

Following are some types of stress:

1. Tensile Stress: It is a stress tending to stretch a body.

1. Bulk Stress: It is an overall force per unit area, also known as pressure.

1. Shear Stress: It is a stress tending to produce an angular deformation.

Strain:

Stress can produce a change in shape, volume or length in an object. This change in the shape of an object is called strain.

Formula:

Mathematically,

Strain = Change in Length/Length or Strain = Change in volume / volume

Units:

2 Since strain is a ratio between two similar quantities, it has no unit.

Following are some types of strain.

1. Tensile Strain: It is a change in length divided by original length.

1. Bulk Strain: It is the change in volume divided by original volume.

1. Shear Strain: It is equal to the angular displacement produced.

Although, of course, listening to books is far from the only way to knowledge. For example, I have a friend who quickly reads books with his eyes. He read a number of books, the same or similar to those that I listened to. It’s more interesting for me to talk to him. It is also worth noting that books are, of course, a bottomless storehouse of knowledge, but far from the only one. 