[LT] light Flashcards
how is visible light represented?
visible light is a form of energy and a part of the electromagnetic spectrum.
what model is used to represent the path taken by light?
the ray model of light is used, which uses straight lines and arrows.
what are the types of light rays?
there are three types: parallel rays, convergent rays, and divergent rays.
define luminous objects.
luminous objects are objects that give off light on their own, such as the sun and lamps.
define non-luminous objects.
non-luminous objects are objects that do not give off light on their own, like the moon and human beings.
what is the reflection of light?
reflection is when light bounces off a surface.
how do non-luminous objects become visible?
light from a source comes into contact with the surface of a non-luminous object > causing certain colors of light to be reflected.
what are the six characteristics of images formed by plane mirrors?
- same size as the object
- upright
- have equal perpendicular
- distances from the mirror
- laterally inverted
- virtual
what are the laws of reflection?
- the first law of reflection states that the angle of incidence is equal to the angle of reflection
- the second law of reflection state that the incident ray, reflected ray, and the normal at the point of incidence all lie in the same plane
name three types of mirrors
plane mirrors, convex and concave mirrors
property of a convex mirror
- curved outwards
- diminishes images
- provides a wider field of vision
property of a concave mirror
- curved inwards
- magnifies images
what are the two types of reflections?
regular reflection > on smooth surfaces
diffused reflection > on rough surfaces
what are the seven steps for constructing ray diagrams?
- locate the image behind the mirror.
- draw the first reflected ray.
- locate the point of incidence.
- draw the first point of incidence.
- draw the second reflected ray.
- draw the second incident ray.
- label
what is the concept of reversibility of light?
light will follow the same path if its direction of travel is reversed
when does refraction of light occur?
refraction of light occurs when
- a light ray passes from one medium to another of different optical density
- the angle of incidence is more than 0 degrees.
how does light behave when it enters a medium of higher optical density?
light bends towards the normal when it enters a medium of higher optical density, slowing it down
how does light behave when it enters a medium of lower optical density?
light bends away from the normal when it enters a medium of lower optical density, quickening it
what is dispersion of light?
it occurs when white light passes through a different medium > causing each of the seven colors to slow down by different extents > and refract by different angles, resulting in the spreading out of colors.
what is the electromagnetic spectrum
the electromagnetic spectrum includes various forms of electromagnetic radiation
what are five applications of the electromagnetic spectrum?
- causing light pollution
- potential damage to eyes
- skin cancer due to overexposure
- producing x-ray images for medical diagnosis
- enabling daily activities.
