Light Flashcards
When going from high refractive to low refractive index, which way does the light bend?
Away from normal.
When going from low refractive to high refractive index, which way does the light bend?
Towards the normal.
How do you draw a ray diagram with a convex lens?
The parallel line is parallel to the principle axis and then going through 1 focal point. Central ray passing throughout the centre (where the lens and axis meet). See photo in book.
Name the () shaped lens.
Convex (Converging)
Name the )( shaped lens.
Concave (Diverging)
What is short sightedness and how can it be corrected?
Can focus on near objects. Far objects converge before the retina. Corrected with a diverging lens.
What is long sightedness and how can it be corrected?
Can focus on far objects. Near objects focus behind the retina. Corrected with converging lens.
What is the equation for reflection?
Angle of incidence = Angle of refraction
What is the rule for dispersion?
BBB - Blue Bends Best
What is the order of colours in dispersion?
Red - Least refracted
Blue - Most refracted
What is the equation for optical power?
Optical Power (D) = 1/Focal Length (m)
In lens diagrams, where does the central ray go?
From the top of the object, through the point where the axis meet.
In lens diagrams, where does the parallel ray go?
From the top of the object, parallel to the principle axis, until the lens, where it bends and goes through the 1st focal point.
