Reflection & Refraction Flashcards
All 7 cards in this deck
What is the law of reflection?
Angle of incidence = angle of reflection (both measured from the normal).
True or false? The angle of incidence is the angle between the ray and the surface of the glass block.
False. It is the angle between the incident ray and the normal (the line at 90° to the surface).
What happens to the speed and direction of a light ray as it passes from air into glass?
e.g. a ray hitting a glass block at 40° to the normal
It slows down and bends towards the normal, so the angle of refraction is less than 40°.
Why does white light split into a spectrum of colours when it is refracted by glass?
The different wavelengths travel at different speeds in the glass, so they refract (bend) by different amounts.
What are the steps to trace a light ray through a rectangular glass block in the core practical?
e.g. using an angle of incidence of
- Draw round the block and draw the normal at the entry point.
- Shine a ray at to the normal; mark the ray going in and coming out with dots.
- Remove the block, join the dots and measure the angle of refraction from the normal.
In the refraction core practical, why is the light source used with a narrow slit?
It produces a single thin ray, so its path can be marked and measured accurately.
In the refraction core practical, what is plotted on each axis of the results graph?
Angle of refraction on the -axis against angle of incidence on the -axis.