Mirrors And Lenses Flashcards
Simplest flat reflective surface mirror
Plane mirror
- reflect perpendicularly or at same angle as normal
- those that are in your house
Convergence vs Divergence mirrors cause:
Concave mirrors cause light rays to converge
Convex mirrors cause light rays to diverge
Where is the focal point on a concave mirror?
Same Side
Where is the focal point on a convex mirror?
Opposite side
Master thin lens equation (and for mirrors)
1/o + 1/i = 1/f
Positive vs negative “i” value in thin lens:
Positive = real (in front of)
Negative = virtual (behind)
Positive vs negative object, “o” value:
+: in front of mirror
-: behind
Positive vs negative focal length value
+: concave: converging
-: convex: diverging
magnification equation
M = -i/o
Magnification pos vs negative
Pos: upright and virtual
Neg: inverted and real
Rays of a ray diagram:
1) Top of the object parallel and intersect focal point
2) Bottom of the image and parallel to normal
- image is intersection of rays
Equation of plane mirror:
Focal length = infinity
O = -I
Magnification is 1
Convex mirror equation
- focal length is < 0
- o > 0 (object in front of mirror)
- i < 0, virtual image behind mirror
- M is positive
Concave mirror thin lens equation
O > 0, F > 0, depends on object distance
- O > F = positive I, real image
M is negative, so real and inverted
Convex mirror produces
- usually smaller, virtual (upright), and behind
Concave mirror can produce
O>F
- pos i: so in front of mirror, positive m: so real and inverted
F>O
- neg i: so behind mirror, negative m: so virtual and upright
Focal point of a mirror is:
Radius / 2
- point where parallel rays of light entering a mirror always converge
Opposite convention of rays for mirrors and lenses
Concave mirror: cause rays to converge
Concave lens: cause rays to diverge
Index of refraction equation:
1/f = (n-1) (1/r1 - 1/r2)
Power of diopter
P = 1/f
Smaller focal length, smaller radius, more sharply curved, bend light more than sphere with larger radius
Nearsighted individuals have what type of lens:
- lens refracts too much
- light converges in front
How is nearsightededness corrected:
Using diverging or concave lens
What is the issue in farsightedness:
Light is not bent sufficiently, light rays converge past retina
How is farsightedness corrected?
use a converging lens to focus light in front of normal focal point on retina
In lenses, positive focal length indicates:
Converging (convex) lens
In lenses, negative focal length indicates:
Diverging, concave lens
Color and absorbance
region of lowest to no absorbance on absorbance spectrum
Convex mirror always has what focal length
- what lens does this relate to
negative: upright and virtual image
relates to concave/divering lens
Concave lens is also called ____
- focal length is?
- relates to what mrriro?
diverging lens (myopia)
- focal length always negative > UV
- relates to convex mirror
focal length related to radius
f = r/2
Equation for diopter
P = 1 / f (in m-1)
Convex lens
- also called?
- relates to what mirror?
- focal length and distance create what type of images
the farther away the object is from the focal length: what happens to image size
Convering lens, related to concave mirror
- d < focal length = upright and virtual
- d > focal length = real and inverted
- the smaller it becomes
