1. Reflection of Light
Definition: Reflection is the phenomenon where light bounces back from a surface into the
same medium.
Key Concepts:
1. Laws of Reflection:
○ First Law: The angle of incidence (∠i) is equal to the angle of reflection (∠r).
○ Second Law: The incident ray, reflected ray, and normal to the surface at the
point of incidence all lie in the same plane.
2. Types of Reflection:
○ Specular Reflection: Occurs on smooth, shiny surfaces like mirrors. The
reflected rays are parallel, producing clear images.
○ Diffuse Reflection: Occurs on rough surfaces, scattering light in many
directions, resulting in no clear image.
3. Plane Mirrors:
○ Characteristics of Image:
■ Virtual and upright.
■ Laterally inverted (left-right inversion).
■ The same size as the object.
■ The distance of the image behind the mirror is equal to the distance of the
object in front.
4. Spherical Mirrors:
○ Concave Mirrors (Converging Mirrors):
■ Curved inward.
■ Can produce real, inverted images or virtual, upright images depending
on the object's position relative to the focal point.
○ Convex Mirrors (Diverging Mirrors):
■ Curved outward.
■ Always produce virtual, diminished, and upright images.
5. Mirror Formula and Magnification:
○ Mirror Formula: 1f=1v+1u\frac{1}{f} = \frac{1}{v} + \frac{1}{u}f1=v1+u1
○ Magnification (m): m=h′h=−vum = \frac{h'}{h} = -\frac{v}{u}m=hh′=−uv
■ Where:
■ f = focal length,
■ v = image distance,
■ u = object distance,
■ h′ = image height,
■ h = object height.
Q&A on Reflection of Light:
Definition: Reflection is the phenomenon where light bounces back from a surface into the
same medium.
Key Concepts:
1. Laws of Reflection:
○ First Law: The angle of incidence (∠i) is equal to the angle of reflection (∠r).
○ Second Law: The incident ray, reflected ray, and normal to the surface at the
point of incidence all lie in the same plane.
2. Types of Reflection:
○ Specular Reflection: Occurs on smooth, shiny surfaces like mirrors. The
reflected rays are parallel, producing clear images.
○ Diffuse Reflection: Occurs on rough surfaces, scattering light in many
directions, resulting in no clear image.
3. Plane Mirrors:
○ Characteristics of Image:
■ Virtual and upright.
■ Laterally inverted (left-right inversion).
■ The same size as the object.
■ The distance of the image behind the mirror is equal to the distance of the
object in front.
4. Spherical Mirrors:
○ Concave Mirrors (Converging Mirrors):
■ Curved inward.
■ Can produce real, inverted images or virtual, upright images depending
on the object's position relative to the focal point.
○ Convex Mirrors (Diverging Mirrors):
■ Curved outward.
■ Always produce virtual, diminished, and upright images.
5. Mirror Formula and Magnification:
○ Mirror Formula: 1f=1v+1u\frac{1}{f} = \frac{1}{v} + \frac{1}{u}f1=v1+u1
○ Magnification (m): m=h′h=−vum = \frac{h'}{h} = -\frac{v}{u}m=hh′=−uv
■ Where:
■ f = focal length,
■ v = image distance,
■ u = object distance,
■ h′ = image height,
■ h = object height.
Q&A on Reflection of Light:
