Concepts Of Physics MCQ Edition [Volume 1]
- Exam
- Concepts Of Physics MCQ Edition [Volume 1]
- Subject
- Physics
- Chapter
- Geometrical Optics
Concepts Of Physics MCQ Edition [Volume 1] · Physics · Geometrical Optics
When studying image formation by spherical mirrors, only paraxial...
When studying image formation by spherical mirrors, only paraxial rays are considered because they
Options
- Acarry most of the intensity of the incident light
- Bproduce nearly a point image from a point source
- Cexhibit a minimal dispersion effect
- Dare geometrically simple to handle
Correct answer
B. produce nearly a point image from a point source
Step-by-step solution
Paraxial rays are the rays that are close to the principal axis and make small angles with it.
For a spherical mirror, rays that are far from the principal axis (marginal rays) do not converge at the same point as paraxial rays after reflection, leading to a blurred image. This phenomenon is known as spherical aberration.
By restricting the consideration to paraxial rays, spherical aberration is minimized, and all the reflected rays from a point object converge at a single point.
Thus, paraxial rays produce nearly a point image from a point source.
For a spherical mirror, rays that are far from the principal axis (marginal rays) do not converge at the same point as paraxial rays after reflection, leading to a blurred image. This phenomenon is known as spherical aberration.
By restricting the consideration to paraxial rays, spherical aberration is minimized, and all the reflected rays from a point object converge at a single point.
Thus, paraxial rays produce nearly a point image from a point source.