Light - Reflection and Refraction Mind Map

Reflection is the bouncing back of light into the same medium after it strikes a surface.

If the ray returns after striking a smooth surface, write reflection; if it bends into a new medium, write refraction.

The laws of reflection state that the incident ray, reflected ray, and normal lie in one plane, and angle of incidence equals angle of reflection.

In ray diagrams, always draw the normal first; most marks are lost because of wrong angle marking.

A spherical mirror is a mirror whose reflecting surface forms part of a sphere.

Always identify the reflecting surface first; inner surface means concave, outer surface means convex.

The focal length is the distance between the pole of a mirror and its principal focus.

If the question gives radius of curvature, remember f = R/2 for a spherical mirror.

The mirror formula relates object distance, image distance, and focal length for spherical mirrors.

Write the sign convention before starting the calculation; it saves many mistakes.

Refraction is the bending of light when it passes from one medium to another because its speed changes.

Always mention both speed change and boundary crossing when explaining refraction.

Refractive index tells us how much a medium slows down light compared with vacuum or air, and how strongly it bends light.

Use the formula given in the question: c/v for speed problems, or sin i/sin r for angle problems.

The lens formula relates object distance, image distance, and focal length for a thin lens.

A real object is usually placed on the left side, so u is negative in the Cartesian sign system.

Power of a lens is the measure of how strongly it converges or diverges light.

Always write the sign of power with the lens type: convex positive, concave negative.

A convex lens can form real or virtual images depending on where the object is placed.

Remember the standard image table for convex lenses; it saves time in both theory and ray-diagram questions.