Question

What is the significance of solid angle in radiation heat transfer. Explain.

Answer 1

Step-by-step explanation:

Solid angle(ω) is also like normal angle .Generally we deal with 1D angles ,but solid angle is a 2D angle.

From the diagram we can say that angle form at the bottom of cone due in 2D ,is called solid angle.The unit of solid angle is steredian.

Solid angle for any surface given as

`\omega =(A)/(R^2)`

Foe sphere
`A=4\pi R^2`

So solid angleω =4π

In radiation solid angle is used to define the intensity of radiation.The intensity of radiation is given as .the rate pf emission of radiation per unit solid angle and per unit projected area in the given direction.