Light Flashcards
What is a luminous object ?
A light source
Something that produces its own light
For example : Sun ,Burning candle
What is a non-luminous object ?
An object that does not produce its own light
What are the two laws of reflection ?
- The angle of incidence = The angle of reflection
2. The incident ray, reflected ray and the normal will always be on the same plane
How do we see non-luminous object ?
We are able to see non-luminous objects because it reflects the light from luminous objects into our eyes. In other words “the reflection of light”
Is moon a luminous or non-luminous object ?
The moon is a non luminous object
The reason why we see it is because it reflects light from the sun into our eyes
What is the symbol of the angle of incidence ? Or incident ray
i
How do we define a ray of light ?
A straight line path which light travels
Which direction does luminous object emit their light ?
They emit light all possible directions
what is the symbol for the angle of reflection ?
r
How does light travel ?
Light travels in a straight line
What is the speed of light in seconds ?
300,000 km/sec
What is refraction ?
The bending of light when it enters a different medium
What is apparent depth ?
How deep something appears to be
What is real depth
How deep something actually is
What is dispersion ?
The splitting of white light into a spectrum of colors
What is a prism ?
A transparent object that refracts light
What are the colors in a spectrum ?
Red Orange Yellow Green Blue Indigo Violet
What are the primary colors?
Red blue and green
What are the secondary colors ?
Yellow , magenta , cyan
What happens when you mix all the primary colors ?
It will make white
Why is white and black not part of the colour spectrum ?
White = combination of all the colors
Black = the absence of light
which colour has the longest wavelength ?
Red has the longest wavelength
Which color has the shortest wavelength ?
Violet has the shortest wavelength
What is the relationship between wavelength and frequency ?
Longer the wavelength = Shorter the frequency
Shorter the wavelength = higher frequency
Which particular color and object appears depends on what ?
The color that is reflected into out eyes
The properties of the object
When light touches and object its either ?
- Reflected
- Absorbed
- Transmitted
When light touches a opaque object what happens ?
It’s either reflected or absorbed
Why do we see color in a object
Because the object is reflecting the particular colors wavelengths of light and absorbing all the other colors .
When light hits an transparent object what happens ?
All of the light is transmitted with only small amount being absorbed or reflected
When light hits a translucent object what happens ?
It only transmits some of the light
How is the color of an translucent object determined
Determined by which colour is transmitted the most
