To find out whether the light bends towards or away the normal from low to high OD objects.
When light travels from a low OD to high OD, it bends towards the normal.
Apparatus and Materials
1) A light box
2) Power pack
There’s no safety procedures.
Independent- The angle of incidence.
Dependent- The direction the light is bended towards, the angle refraction.
Controlled- Light output.
Step by step:
1)Plug lightbox to power pack.
2) On light box and shine at perspex’s normal, not perpendicularly.
3) Compare the angle of incidence to the angle of reflection, which angle is bigger?
4) Write results.
5) Repeat 2,3,4.
|Angle of Incidence||44||63||6|
|Angle of Refraction||25||37||3|
What: When light travels from air to perspex, it always bends towards the normal.
Why: The angle of refraction is always lesser than the angle of incidence.
Reliability: Three angles of incidences were collected to make this reliable.
With one angle nearest to and one furthest from the normal as possible while the third one in between.
Using a light box makes the light beam considerably focused makes the results more accurate as well.
Strengths: By placing the paper under the perspex, it was easy to change the angle of incidence without
adjusting it again so it shines on to the normal. Using the pencil and ruler, it was easy to draw the light beam
path and then measure it using a protractor.
Improvements: If there was a laser pointer that shows not only it’s start and end point but also it’s path,
it will be much more accurate on drawing the line of the light as white light expands the further it goes.
Using a compass would also making drawing the line of light much more accurate as it will be more convenient.
Validity: Overall, it is a fair and accurate test however, most of the measurements are off by 1-4 degrees. This
could be resolved.
The hypothesis is supported as no matter what the angle of incidence is, the angle of refraction is always lower.