lenses. Flashcards
what should you assume in a ray diagram?
assume refraction occurs at the middle of the lens.
what are the two types of lenses called?
convex and concave.
how could you describe the rays in a convex lens?
thicker in the middle than at the edge.
where is the focal point on a convex ray diagram?
where all the rays cross and meet each other.
how could you describe the rays in a concave lens?
thinner in the middle than edge.
where is the focal point on a concave ray diagram?
where the middle ray is between the 2 arrows.
what lens does a convex lens have?
converging lens.
what lens does a concave lens have?
diverging lens.
how do you measure the focal length of a convex lens?
focus/ form the image of a distant object on to a piece of paper.
what does the distance between the lens and the paper give us?
focal length of the lens.
how would you fix short sightedness?
use a diverging lens.
what does a diverging lens do?
spreads the rays out slightly so they focus on the retina.
