Light - Reflection & Refraction Flashcards
(30 cards)
Light travels in ____ line.
Straight
What is diffraction of light?
When an opaque object is so small,light bends instead of travelling straight.
Theory of light states that light is neither a ____ nor a ____.
Wave, Particle
Principal axis is _____ to the mirror at its pole.
Normal
What is an aperture?
The diameter of the reflecting surface of a spherical mirror
When is an image formed?
When two rays intersect.
What are the uses of concave mirror?
Torches, search lights, vehicle headlights, shaving mirrors, used by dentists, solar furnaces
Why does the light rays come back along the same path when a ray passes through centre of curvature?
Because the incident ray fall on the mirror along with the normal.
In what mirror can you see a full length image of an object?
Convex mirror
What mirror is fitted in a wall of Agra fort facing the Taj Mahal?
Convex mirror
What are the uses of convex mirror?
Rear view mirrors, device to check thefts
All distances parallel to the principal axis are measured from the ____ of the mirror.
Pole
A negative magnification indicates the image is _____ and a positive magnification indicates the image is____.
Real ; Virtual
The height of the object is positive or negative?
Positive.
Does light travel in the same direction in all media?
No
What is optically denser and rarer medium?
A medium in which the speed of light is more is known as rarer medium and vice versa.
What happens when light enters from a rarer to denser medium?
Light bends towards normal.
What is the speed of light in vacuum?
3 x 10^8 m s-1
What is absolute refractive index of the medium?
The refractive index of any medium with respect to vacuum or air
A media with a larger refractive index is optically denser or rarer?
Denser
What is a lens?
A transparent material bound by two spherical surfaces.
What happens to a ray of light passing through the optical centre of a lens?
It passes without any deviation.
What are thin lenses?
Lenses whose aperture is smaller than its radius and 2 centres of curvature.
Plural of principal focus
Principal foci
