Optics- Reflection of Light and Formation of Images
Reflection of ray parallel to the principal axis
Incident ray
Reflected ray
Normal
Angle of incidence
Angle of reflection
Optics- Reflection of Light and Formation of Images
Laws of reflection
First law: Incident ray, reflected ray, and the normal all lie on the same plane
Second law: Angle of incidence is equal to the angle of reflection
Optics- Reflection of Light and Formation of Images
Formation of images by a plane mirror
Virtual image
Laterally inverted
Same size as the object
Same distance behind the mirror as the object is in front of it
Erect
Optics- Reflection of Light and Formation of Images
Ray diagrams for formation of images by a plane mirror
Object at infinity
Object between infinity and pole
Object at pole
Object between pole and focus
Object at focus
Optics- Reflection of Light and Formation of Images
Reflection of light by curved surfaces
Concave mirror
Convex mirror
Center of curvature
Principal axis
Focal length
Optics- Reflection of Light and Formation of Images
Focal length of a concave mirror
Focal point
Focal length
Relationship with radius of curvature
Positive focal length for concave mirror
Optics- Reflection of Light and Formation of Images
Ray diagrams for concave mirror
Object at infinity
Object beyond C
Object at C
Object between C and F
Object at F
Optics- Reflection of Light and Formation of Images
Sign convention for mirror formula
Object distance (u)
Image distance (v)
Focal length (f)
Positive and negative values
Optics- Reflection of Light and Formation of Images
Mirror formula
Relationship between object distance, image distance, and focal length
1/f = 1/v + 1/u
Optics- Reflection of Light and Formation of Images
Magnification
Relationship between height of the image and height of the object
Magnification (m)
m = h’/h = -v/u
Optics- Reflection of Light and Formation of Images
Reflection of ray parallel to the principal axis
Incident ray is parallel to the principal axis
Reflected ray passes through the focus
Image is formed at the focus
Example: When a parallel beam of light falls on a concave mirror
Optics- Reflection of Light and Formation of Images
Ray diagrams for reflection parallel to the principal axis
Object at infinity
Object beyond C
Object at C
Object between C and F
Object at F
Example: Ray diagram for a concave mirror with an object at infinity
Optics- Reflection of Light and Formation of Images
Reflection of ray through the center of curvature
Incident ray passes through the center of curvature
Reflected ray retraces its path
Image is formed at the same location as the object
Example: When a beam of light falls on a concave mirror along its principal axis
Optics- Reflection of Light and Formation of Images
Ray diagrams for reflection through the center of curvature
Object at infinity
Object beyond C
Object at C
Object between C and F
Object at F
Example: Ray diagram for a concave mirror with an object at the center of curvature
Optics- Reflection of Light and Formation of Images
Reflection of ray passing through the focal point
Incident ray passes through the focal point
Reflected ray becomes parallel to the principal axis
Image is formed at infinity
Example: When a beam of light falls on a concave mirror along a line that passes through its focus
Optics- Reflection of Light and Formation of Images
Ray diagrams for reflection passing through the focal point
Object at infinity
Object beyond C
Object at C
Object between C and F
Object at F
Example: Ray diagram for a concave mirror with an object at the focal point
Optics- Reflection of Light and Formation of Images
Concave mirrors and their applications
Magnifying mirrors
Headlights of vehicles
Reflectors in torches
Telescope mirrors
Example: Uses of concave mirrors in our daily life
Optics- Reflection of Light and Formation of Images
Convex mirrors and their applications
Rear-view mirrors in vehicles
Security mirrors in stores
Traffic mirrors at blind spots
Example: Uses of convex mirrors in different situations
Optics- Reflection of Light and Formation of Images
Formation of images by convex mirrors
Virtual image
Diminished in size
Image formed behind the mirror
Example: The formation of an image in a convex mirror
Optics- Reflection of Light and Formation of Images
Ray diagrams for formation of images by convex mirrors
Object at infinity
Object beyond C
Object at C
Object between C and F
Object at F
Example: Ray diagram for a convex mirror with an object at infinity
Optics- Reflection of Light and Formation of Images
Reflection of ray parallel to the principal axis
Incident ray is parallel to the principal axis
Reflected ray passes through the focus
Image is formed at the focus
Example: When a parallel beam of light falls on a concave mirror
Optics- Reflection of Light and Formation of Images
Ray diagrams for reflection parallel to the principal axis
Object at infinity
Object beyond C
Object at C
Object between C and F
Object at F
Example: Ray diagram for a concave mirror with an object at infinity
Optics- Reflection of Light and Formation of Images
Reflection of ray through the center of curvature
Incident ray passes through the center of curvature
Reflected ray retraces its path
Image is formed at the same location as the object
Example: When a beam of light falls on a concave mirror along its principal axis
Optics- Reflection of Light and Formation of Images
Ray diagrams for reflection through the center of curvature
Object at infinity
Object beyond C
Object at C
Object between C and F
Object at F
Example: Ray diagram for a concave mirror with an object at the center of curvature
Optics- Reflection of Light and Formation of Images
Reflection of ray passing through the focal point
Incident ray passes through the focal point
Reflected ray becomes parallel to the principal axis
Image is formed at infinity
Example: When a beam of light falls on a concave mirror along a line that passes through its focus
Optics- Reflection of Light and Formation of Images
Ray diagrams for reflection passing through the focal point
Object at infinity
Object beyond C
Object at C
Object between C and F
Object at F
Example: Ray diagram for a concave mirror with an object at the focal point
Optics- Reflection of Light and Formation of Images
Concave mirrors and their applications
Magnifying mirrors: Used for applying makeup or shaving
Headlights of vehicles: To focus the light and illuminate the road
Reflectors in torches: To produce a beam of light
Telescope mirrors: To collect and focus light
Example: Uses of concave mirrors in our daily life
Optics- Reflection of Light and Formation of Images
Convex mirrors and their applications
Rear-view mirrors in vehicles: To provide a wide field of view
Security mirrors in stores: To eliminate blind spots
Traffic mirrors at blind spots: To enhance safety
Example: Uses of convex mirrors in different situations
Optics- Reflection of Light and Formation of Images
Formation of images by convex mirrors
Virtual image is formed
Image is diminished in size
Image is formed behind the mirror
Example: The formation of an image in a convex mirror
Optics- Reflection of Light and Formation of Images
Ray diagrams for formation of images by convex mirrors
Object at infinity
Object beyond C
Object at C
Object between C and F
Object at F
Example: Ray diagram for a convex mirror with an object at infinity