Question

what you know about solid angle concept?

Answer 1

Solid angle is a two dimensional angle subtended by any part of a spherical surface of unit radius at its center. It is a dimensionless quantity. Its SI unit is ‘Steradian’ in brief ‘sr’. It is usually denoted by ΩΩ or ωω

If a part of spherical surface of radius rr has an area AA then the solid angle subtended by this area at the center of sphere is mathematically given as

Ω=area of part of spherical surface(radius)2=Ar2Ω=area of part of spherical surface(radius)2=Ar2

Answer 2

a solid angle made up of all lines from a closed curve meeting at vertex, defined by surface area of a sphere subtended by the line

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