Required Practicals (Paper 2) Flashcards
Describe a method to investigate the reflection of light by different types of surface and the refraction of light by different substances
- place a glass block on a piece of paper
- draw around the glass block
- use the ray box to shine a ray of light through the glass block
- mark the ray of light entering the glass block
- mark the ray of light emerging from the glass block
- join the points to show the path of the complete ray through the block
- and draw a normal line at 90 degrees to the surface
- use a protractor to measure the angle of incidence
- use a protractor to measure the angle of refraction
- increase the angle of incidence in 10 degree intervals
- Repeat steps 2 to 7 for a block of different material
- Measure the angle of incidence, refraction and reflection for each block.
- Compare results
CVs - distance of ray box from mirror, width of the light beam, same frequency/wavelength of the light
the angles of incidence and reflection will be the same for any materials (as not affected by them), but refraction will change
Draw a ray diagram for the refraction experiment
Note: the incident ray and emergent ray are parallel - make this clear
How do you draw the normal?
A dashed line perpendicular to the surface
Why would using a wider ray give less accurate results than a narrower one?
harder to judge where the centre of the wider ray is
causing a larger uncertainty
How could the change the apparatus of a reflection experiment if they want to investigate diffuse reflection?
Replace the (plane) mirror with an irregular reflecting surface
What may have lead to an error when measuring the angle of reflection?
not placing mirror / ray box in the same position
How could you develop the angle of reflection/incidence experiment further?
results could be collected for angles (of incidence) not yet measured
