P14 - Light (PAPER 2) Flashcards
What is the normal at a point on a mirror
a line drawn perpendicular to the mirror
What does the law of reflection state
angle of incidence = angle of reflection
What is specular reflection
a reflection in a single direction without scattering
What is diffuse reflection
a reflection from a rough surface that scatters the light
What is refraction
the change in direction of waves when they travel across a boundary from one medium to another
How does the wavelength of light change from violet to red on the colour spectrum
at violet it is shortest, but increases the further down the spectrum
How does the colour of a surface change
it depends on what wavelengths of light the pigments can absorb
What is a translucent object
an object which lets light through but scatters or refracts the light inside it
What is a transparent object
An object hat lets all light through and does not scatter or refract the light inside it
What is a convex lens
a lens that focuses parallel rays to a point called the principal focus
What is a concave lens
a lens that makes parallel rays spread out as if they had come from a point called the principal focus
When is a real image formed with a convex lens
when the object is further away than the principal focus
When is a virtual image formed with a convex lens
when the object is closer than the principal focus
what is the formula for calculating magnification
magnification = image height / object height
What does a ray diagram help find
the position and nature of an image formed by a lens
