The angle which the periphery of the spherical mirror subtends at the center of curvature is called
angular aperture
glancing angle
Critical angle
None of these
angular aperture
Correct Answer- A
The angle at which the periphery of the spherical mirror subtends at the center of curvature is called the angular aperture.
Incorrect answers
B- The glancing angle is the angle formed by the incident ray on a planar surface and the surface itself.
A beam of electrons striking the crystal is an example of a glancing angle.
B- The critical angle is the angle of incidence that produces a 90-degree angle of refraction.
So, the correct answer is (A) angular aperture.