Concepts to Remember on Reflection of Light and Formation of Images

1. Laws of reflection:

• The incident ray, the normal to the surface at the point of incidence, and the reflected ray all lie in the same plane.
• The angle of reflection is equal to the angle of incidence.

2. Mirror equation:

• 1/f = 1/d_o + 1/d_i
• where f is the focal length, d_o is the object distance, and d_i is the image distance.

3. Formation of images by plane and spherical mirrors:

• Real images: Formed by the convergence of reflected rays. Can be projected onto a screen.
• Virtual images: Formed by the divergence of reflected rays. Cannot be projected onto a screen.

4. Magnification:

• The ratio of the image height to the object height.
• M = h_i/h_o = -d_i/d_o

5. Reflection from curved surfaces:

• Converging mirrors (concave): Cause rays to converge at a single point.
• Diverging mirrors (convex): Cause rays to diverge as if they were coming from a virtual point.

6. Focal length:

• The distance between the mirror and the point where parallel rays converge for a converging mirror or the point from which parallel rays appear to diverge for a diverging mirror.

7. Sign convention for spherical mirrors:

• Distances are positive if measured in the direction of the principal axis and negative if measured in the opposite direction.
• Object distances are negative for virtual objects.
• Image distances are negative for virtual images.

8. Ray diagrams for the formation of images by spherical mirrors:

• Used to graphically determine the location and characteristics of images formed by spherical mirrors.

9. Types of mirrors:

• Concave mirrors: Converging mirrors with a reflecting surface curved inward.
• Convex mirrors: Diverging mirrors with a reflecting surface curved outward.

10. Uses of mirrors:

• Shaving mirrors: Allow for a person to see their face clearly.
• Car rearview mirror: Allow drivers to see the area behind their car.
• Telescope: Used to magnify distant objects.