optics part 2

Question 1

Concave lenses:
what are the ray laws?
+ whats the salt

Answer 1

1) PA -> F (L)
2) F’ -> PA
3) Through O

smaller, upright, same side as object, virtual

Question 2

Convex lenses:
what are the ray laws?
+ whats the salt

Answer 2

1) PA -> F (R)
2) F’ (L) -> PA
3) Through O
sm,sa,l,x,l
inverted, x, up
real, x, virtual

Question 3

Convex lens, object at 2F

Answer 3

same, inverted, AT 2F, real

At 2F : diagram may be off due to curvature

Question 4

Convex lens, object is getting closer

Answer 4

between F & 2F
At 2F
Beyond 2F
Same side as object

Question 5

Convex lens at F’

Answer 5

No image formed !

Question 6

What type of mirror is diverging?

Answer 6

Concave

Question 7

What type of mirror is converging?

Answer 7

Convex

Question 8

What is presbyopia?

Answer 8

A form of far-sightedness.
Eye loses its elasticity when ppl get older.
Can be corrected by glasses.

Like reading glasses

Question 9

What is myopia?

Answer 9

Near-sightedness. Condition in which eye cannot focus on distant objects. Light rays converge too early, thus image doesnt form at retina.

To correct it: DIVERGING / CONVEX, negative meniscus

Question 10

What is hyperopia?

Answer 10

Far sightedness. Eye cannot focus on nearby objects. Light rays converge too late, thus image doesnt form at retina.

To correct it: CONVERGING / CONCAVE, positive meniscus

Question 11

How does lasik eye surgery work?

Answer 11

• Separate thin layer from front of cornea
• Laser sculpts the cornea bed into corrective shape
• Laser reshapes it so when light enters the eye lens it refracts appropriately to allow light rays to form image at retina.