1 thought on “If arperture of mirror increased then what will be its focal length?–increase or decrease. please answer correctly”
Explanation:
spherical mirror, the diameter of the aperture cannot be more than twice the radius of curvature. Such a mirror would have a significant spherical aberration. A large aperture mirror that can focus parallel incident light into a point would need to have a parabolic shape, such a lens would have no (theoretical) limit on its size. Spherical mirrors do not focus parallel light rays to a single focal point. The point of using an aperture much smaller that the radius of the mirror is to restrict the incoming light to a region where rays do come to a single focal point
Explanation:
spherical mirror, the diameter of the aperture cannot be more than twice the radius of curvature. Such a mirror would have a significant spherical aberration. A large aperture mirror that can focus parallel incident light into a point would need to have a parabolic shape, such a lens would have no (theoretical) limit on its size. Spherical mirrors do not focus parallel light rays to a single focal point. The point of using an aperture much smaller that the radius of the mirror is to restrict the incoming light to a region where rays do come to a single focal point