waves - convex lenses

Question 1

describe look of convex lens

Answer 1

thicker at the centre than the edges

Question 2

symbol for convex lens

Answer 2

vertical long arrow

Question 3

all lenses….

Answer 3

refract light

Question 4

what happens when light passes into lens and out

Answer 4

light ray bends towards the normal then bends away from normal

Question 5

what happens when parallel rays of light passes into lens through a convex lens?

Answer 5

• central ray passes through the lens without being refracted as it is passing directly along the normal (principal axis - centre)
• all other rays refract on a focused point called principal focus (F)

Question 6

what is the focal length?

Answer 6

the distance from the centre of the lens to the principal focus

Question 7

what do different convex lenses have?

Answer 7

different focal points depending on the strength of the lens

Question 8

how to create a ray diagram from a focal lens?

Answer 8

• object at least 2 focal lengths away from the lens
• draw line from top of object passing through centre of lens without changing direction
• another line from top of object to top of convex lens that is parallel to principal axis. when line hits the lens it is refracted through the principal focus
• where 2 lines meet show us top of the image

Question 9

what happens if object is more than 2 focal lengths from the lens?

Answer 9

image is diminished, inverted and real (where lines meet)

Question 10

what happens if object is between 1 and 2 focal lengths from the lens?

Answer 10

image is magnified, inverted and real