Question

The total solid angle subtended at a point inside cube by it's total surface is
2π rad
4π rad
π rad
0 rad​

Answer 1

Option “B” is correct i.e. 4 π radians.

• The total solid angle that is subtended at a point inside the cube by its total surface is 4 π radian.

• A steradian is mainly a solid angle that is subtended at the middle of a sphere of radius r by a unit of its surface area of magnitude equivalent to r2.  

• Because the surface area is 4πr2, there are 4π steradians adjacent to a point in space.

Hope it helped...