Light And Sight Flashcards
Uses of laser light
CD players,medical operations,library checkouts,scanners
What is a ray ?????
The direction in which a light is travelling is called a ray
What is a beam ?????
A beam is a stream of light and is shown by a num of rays
Three types of beams ????
- diverging - going out
- converging - coming in
- parallel - going straight
What are the two reasons for a shadow to form ??????
Reason 1 - an opaque object does not allow it to pass
Reason 2 - when a straight light passes
What is umbra and penumbra ?????
Theses two occur only with an extended source light …..the dark region is umbra and the lighter part is penumbra ……:)
What is luminous and non-luminous source mean
Luminous sources radiate light by its own and non luminous sources reflect the real light
Law of reflection …..
The angle of incident is equal to the angle of reflection
How is a plane mirror made???
With a plane glass coated with a silver sheet at the back
Periscope : is made
It is Made with two glasses facing each other at an angle of 45 degrees
What is a lateral image ???
It is basically opposite image of the rays
