Light Flashcards
(67 cards)
What is reflection?
Bouncing back of light in the same medium
What is the law of reflection
The incident ray reflected ray and normal all lies on the same plane.
Angle of incidence= angle of reflection
What are the types of spherical mirrors?
Concave mirror - caved part is reflective. Converging
Convex mirror - bulging out reflecting mirror. Diverging
What are the types of image ?
Real and inverted image - can be obtained on screen. Formed when light rays actually meet
Virtual and erect image - cannot be obtained on the screen. formed when light rays appear to meet
What is the centre of curvature and radius of curvature
It is the centre of the mirror denoted by C.
Radius of curvature is the distance between the centre of curvature and pole denoted by R.
Where is focus and focal length ??
It lies between the centre of curvature and pole denoted by F.
Focal length is the distance between focus and pole denoted by f.
What is pole ?
It is the centre of the mirror surface
What is the principal axis?
An imaginary line passing through C F and P.
What is the relationship between f and R
f=R/2
When the incident ray is parallel to the principal axis it passes through …….
Focus (F)
When the rays of light come from infinity they are ………..
Parallel
If a ray of light passes through focus after reflection then it is ………..
Parallel to principal axis
If the incident ray passes through Centre of curvature it ………..
Bounces back at the same path forming 0°
When the reflected ray passes through the pole it reflects ………
Obliquely angle of incidence= angle of reflection both made by principal axis
Concave mirror
When an object is at infinity ♾️
The image formed is highly diminished real and inverted and is formed at focus.
Concave mirror
When an object is kept beyond C
The image formed is real and inverted between C and F and smaller / diminished.
Concave mirror
When an object is kept at C
The image formed is real and inverted at C and is of the same size.
Concave mirror
When an object is placed between C and F
The image formed is beyond C larger and real and inverted.
Concave mirror
When an object is kept at F
The image formed would be at infinity and real and inverted larger.
Concave mirror
When the object is between F and P
The image formed is behind the mirror virtual and erect and enlarged
What are the uses of concave mirrors?
Used in shaving mirror headlight solar furnace and also by dentists.
Dentists need an enlarged, virtual image as the object is kept near the mirror the image formed is enlarged and erect.
In the solar furnace and headlight a strong parallel beam of light is required.
Convex mirror
When an object is at infinity
Image is formed at focus virtual and erect and highly diminished
Convex mirror
When the object is between infinity and Pole.
The image is formed between P and F virtual and erect smaller or diminished.
What are the uses of a convex mirror?
Used where a wide field of view is required like parking mirrors and rear view mirrors.