Light and Sound Physics Flashcards
What type of wave is light?
Transverse wave
Vibrations are perpendicular to the direction of wave travel.
Does light need a medium to travel?
No
Unlike sound, light can move through space.
What is the Law of Reflection?
Angle of incidence = Angle of reflection
Angles are measured from the normal.
What type of reflection occurs on smooth surfaces?
Regular reflection
Produces clear images.
What type of reflection occurs on rough surfaces?
Diffuse reflection
Scattered light, no clear image.
What is an incident ray?
Incoming ray of light
It strikes the surface before reflection.
What is a refracted ray?
Light bending inside the medium
Occurs after passing into a new medium.
What is refraction?
Bending of light when it moves from one medium to another
Happens due to a change in speed of light.
What happens to light when it moves from air to a denser medium like glass?
Slows down and bends towards the normal
The opposite occurs when moving to a less dense medium.
What does the refractive index (n) measure?
How much light bends in a material
Higher n means greater bending.
What is the formula for refractive index?
n = sin(i) / sin(r)
Where i is the angle of incidence and r is the angle of refraction.
What is Total Internal Reflection (TIR)?
When light cannot escape a medium and is completely reflected inside
Occurs when conditions are met.
What are the conditions for Total Internal Reflection?
- Light travels from denser to less dense medium
- Angle of incidence is greater than the critical angle
Example: Glass to air.
What is the critical angle (c)?
The angle when light refracts at 90° along the boundary
If i > c, Total Internal Reflection occurs.
How is the critical angle calculated?
sin(c) = 1/n
n is the refractive index of the medium.
