Paraboloid MirrorHardQuestion 20206
Question
Parabolic mirrors (used in searchlights and satellite dishes) are preferred over spherical mirrors because:
- AThey are cheaper to manufacture
- BThey eliminate spherical aberration — all parallel rays reflect to exactly one focusCorrect
- CThey have larger focal length
- DThey work for only visible light
Correct answer
They eliminate spherical aberration — all parallel rays reflect to exactly one focus
Explanation
Spherical mirrors have aberration for wide beams (marginal rays focus closer than paraxial rays). A parabolic mirror has an exact focus for all parallel rays — used in telescopes, searchlights, and satellite dishes.