Question

what is the formula of steradian in terms of a and r​

Answer 1

Answer:

A steradian can be defined as the solid angle subtended at the center of a unit sphere by a unit area on its surface. For a general sphere of radius r, any portion of its surface with area A = r2 subtends one steradian at its center. sr is the unit, steradian.

Explanation:

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Answer 2

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A steradian can be defined as the solid angle subtended at the center of a unit sphere by a unit area on its surface. For a general sphere of radius r, any portion of its surface with a certain area A = r2 subtends one steradian at its center.

A graphical representation of 1 steradian.

The sphere has radius r, and in this case the area A of the highlighted surface patch is r2. The solid angle Ω equals [A/r2] sr which is 1 sr in this example. The entire sphere has a solid angle of 4π sr.

(please refer to the given attachment)

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