Light

Question 1

Speed of light in vacuum

Answer 1

3.00 x 10^8 m s^-1

Question 2

c in n=c/v

Answer 2

Speed of light in vacuum

Question 3

n in n=c/v

Answer 3

Refractive index of medium
(Usually reserved for absolute refractive index)

Question 4

v in n=c/v

Answer 4

Speed of light in medium

Question 5

How to get absolute refractive index

Answer 5

n = c/v
“c” is the speed of light in a vacuum,
“v” is the speed of light in the material
“n” is the index of refraction.

Question 6

Snells law

Answer 6

(Refractive index of a)(sin angle of incidence) =
(Refractive index of b)(sin angle of refraction)

nA sin 0A = nB sin 0B

Question 7

What angle is the same as critical angle

Answer 7

angle of incidence

Question 8

whats the critical angle

Answer 8

when light exits an optically denser medium at a specific angle of incidence known as the critical angle, the maximum angle of refraction of 90deg to the normal(flat) takes place

Question 9

critical angle formula

Answer 9

sin^-1* (n2/n1)

n2 is the refractive index of the less dense medium
n1 is the refractive index of the denser medium

this si because critical angle occurs from when light travels from an optically denser medium to an optically less dense medium

Question 10

how can u use depth to calculate refractive index

Answer 10

n = real depth/apparent depth

Question 11

whats the relationship focal length((f), distance of object from lens (u) and distance of image from lens(v) have

and whats different for virtual images

Answer 11

1/f = 1/u + 1/v
in virtual images the v is a negative number

Question 12

f in 1/f = 1/u + 1/v

Answer 12

focal length

Question 13

u in 1/f = 1/u + 1/v

Answer 13

distance of object from lens

Question 14

v in 1/f = 1/u + 1/v

Answer 14

distance of image from lens

Question 15

if the object is beyond 2f, what is the properties of the image

Answer 15

real, inverted, diminished

Question 16

if the object is 2f, what is the properties of the image

Answer 16

real, inverted, equal

Question 17

if the object is between 2f and f, what is the properties of the image

Answer 17

real, inverted, magnified

Question 18

if the object is f, what is the properties of the image

Answer 18

no image as no light converges

Question 19

if the object is between f and o, what is the properties of the image

Answer 19

virtual, upright, magnified

Question 20

magnification formula

Answer 20

M = v/u
distance of object from lens (u)
distance of image from lens(v)

Question 21

whats the requirements for light to refract

Answer 21

different mediums shouldve have different absolute refractive indices. if 2 mediums have similar absolute refractive indices, the speed of light will not change in them and light would not refract or bend

Question 22

whats a condition needed for critical angle to occur

Answer 22

light travels from an optically denser medium to an optically less dense medium

Question 23

pro air time skip for snells law

Answer 23

air is a
other medium is b
n.b = sinθa / sinθb
(refractive index of 2nd medium) =
(sin incidence from air)/(sin refractive out to 2nd medium)

Question 24

uses of a glass prism vs mirror or polished surface

Answer 24

1. surface does not corrode like a silver surface
2. light energy is fully reflected at the boundary.
3. multiple reflections are not an issue with prisms
4. can be made to fit into smaller optical equipment where mirrors cannot be effectively used.

Question 25

describe optic fibres

Answer 25

optic fibres make use of **total internal reflection** to transmit light signals. Multiple total internal reflection takes place along the entire length of the uniform glass fibre that is **layered with an optically less dense material.** however, booster units are needed to enhance the light signal after some distance

Question 26

principle of reversibility

Answer 26

light will retrace its path when you reverse the light

Question 27

magnification formula by (distance between object and lens) and (distance between image and lens)

Answer 27

M = v / u

Question 28

what do parallel rays signify usually

Answer 28

light rays from infinity

Question 29

how to find the focal point for a infinity ray graph with no information other than 2 parrallel rays coming down

Answer 29

the point where they converge is the focal length, below/ above = to the focal point

Question 30

Less dense to dense, where will light bend towards

Answer 30

it slows down and bends **towards** the normal.

Question 31

Denser to less dense, where will light bend towards

Answer 31

it speeds up and bends **away** from the normal.

Question 32

define absolute refractive index

Answer 32

the **ratio** of **speed of light in vacuum** (c), to that of the **speed of light in medium** (v),

Question 33

range of values of absolute refractive index

Answer 33

the absolute refractive index is always greater than 1

Question 34

what is the relative refractive index

Answer 34

it is the ratio between 2 absolute refractive indexes or speed of light in 2 mediums

Question 35

how to get the relative refractive index

Answer 35

n2/n1 asolute refractive index n2 (entering medium) / n1 (leaving medium) or v1/v2 speed of light v2 (entering medium) / v1 (leaving medium) The speed of light in a medium is inversely proportional to its refractive index.

Question 36

(range of values/ratio) of relative refractive index

Answer 36

relative refractive index may be greater than or smaller than unity(1:1)