Light And Optics

Question 1

Law of reflection:

Answer 1

angle of reflection = angle of incidence

*with respect to Normal

Question 2

Equation to determine index of refraction:

Answer 2

n = ^c/_v

Question 3

What happens to light as a goes from a less dense medium (small index of refraction) to a more dense medium (higher index of refraction)?

Answer 3

wavelength becomes shorter, the wave travels slower

Bends toward Normal

Question 4

What happens to light as a goes from a more dense medium (high index of refraction) to a less dense medium (lower index of refraction)?

Answer 4

wavelength increases, light ray travels faster

Bends away from Normal

Question 5

Energy of a photon equation:

Answer 5

E = hf

Question 6

Equation to determine wavelength:

Answer 6

λ = ^c/_f

Question 7

Snell’s Law:

Answer 7

n₁sinθ₁ = n₂sinoθ₂

describes angle of refraction in relation to index of refraction. As the angle of refraction increases, the index of refraction decreases.

Question 8

What wavelengths of light are most affected by refraction?

Answer 8

shorter wavelengths:

Violet will refract the most and red will refract the least; the frequency never changes, only the wavelength does

Question 9

A converging system is one in which light rays:

Answer 9

converge

Question 10

A diverging system is a system in which light rays:

Answer 10

diverge

Question 11

The two converging systems:

Answer 11

concave mirrors

convex lens

Question 12

The two diverging systems:

Answer 12

convex mirror

concave lens

Question 13

Equation to determine focal length from object distance and image distance:

Answer 13

¹/_f = ¹/_o + ¹/_i

f = focal distance in m

o = object distance in m

i = image distance in m

Question 14

Equation to determine magnification:

Answer 14

m = -ⁱ/o

|m| < 1 = reduced

|m| > 1 = magnified

|m| = 0 = same size

-m = inverted

+m = upright

Question 15

|m| < 1 =

Answer 15

reduced

Question 16

|m| > 1 =

Answer 16

magnified

Question 17

|m| = 0 =

Answer 17

same size

Question 18

-m =

Answer 18

inverted

Question 19

+m =

Answer 19

upright

Question 20

focal length for spherical mirrors (concave or convex):

Answer 20

f = ¹/₂r

r = radius of curvature in m

Question 21

Three rules for converging mirrors and lenses:

Answer 21

Converging = concave mirrors and convex/convex lenses:

1) **F < o = IR **(inverted / real)
2) **F = o = NO **(no image)
3) **F > o = UV **(upright / virtual)

Question 22

Single rule for diverging mirrors and lenses:

Answer 22

diverging = convex mirrors and concave/convex lenses:

1) **UV_min **(upright / virtual / minimized)

Question 23

Converging mirror and lenses magnification rules:

Answer 23

1) 2f > o > f = enlarged
2) 2f = o = same size
3) 2f < o = minimized

Question 24

When is f positive and negative?

Answer 24

positive = converging

negative = diverging

Question 25

When is i positive and negative?

Answer 25

positive = real

negative = virtual

Question 26

When is o positive and negative?

Answer 26

positive = same side as light ray

negative = opposite side of light ray

Question 27

When is m positive and negative?

Answer 27

positive = upright

negative = inverted

Question 28

Chromatic aberration cause:

Answer 28

dispersion of light due to refraction; only applicable to lenses

Question 29

Spherical abberation cause:

Answer 29

imperfections in the spherical surface of a lens or mirror

less spherical = more imperfections

Question 30

For a combination lens system, what is the total magnification?

Answer 30

M_total = (m₁)(m₂)

Question 31

Equation to determine the critical angle:

Answer 31

sin(θ_c) = ^nr/_ni

nr = the refractive medium

ni = the incident medium

Question 32

When light hits a medium at an angle equal to or greater than the critical angle, what occurs?

Answer 32

total internal reflection; the light ray is reflected back into the incident medium