What is reflection?
When waves bounce back after meeting a boundary.
What is the point of incidence?
The point at which the light ray hits the boundary.
What is a boundary?
A surface which separates two media.
What is a normal?
The perpendicular line drawn to the boundary at the point of incidence.
What is angle of incidence?
Angle between the normal and the incident ray.
What is angle of reflection?
Angle between the normal and reflected ray.
What is incident ray?
Ray which is travelling towards the boundary.
What is reflected ray?
The ray bouncing back to the same medium.
What is refraction?
Refraction occurs due to the change in the speed of a wave when going from one medium to another. Due to the speed change, the energy propagation can also change.
What is energy propogation?
The direction of a wave.
Draw examples of refraction:
When light travels from a rarer medium to a denser medium.
When light travels from a denser medium to a rarer medium.
When the light ray direction is parallel to the normal.
Rarer-> Denser
Slows down + goes towards normal
Denser-> Rarer
Speeds + moves away from normal
What is the constant of a wave, regardless of whatever medium it goes through?
Frequency of a wave is unique and will never change when it moves from one medium to another.
Wavelength is directly proportional to…
Speed.
When speed increases, wavelength increases, and vice versa.
What happens to an image in the mirror?
It is laterally inverted.
Draw a ray diagram of someone being reflected in the mirror.
What is the apparent position?
An position where the object seems to appear, when in reality it is elevated from the real position of the object.
Draw a refraction diagram with apparent position.
Properties of an emergent ray:
-Parallel to incident ray.
-Shifted sideways from the direction of the incident ray. This is known as laterally displacement.
Draw a diagram of a light ray passing through:
a) a rectangular glass block
b) a semicircular glass block
What is a critical angle?
When a light ray goes from a denser medium to a rarer medium, the angle of incidence at which the refracted ray goes along the boundary is known as the critical angle.
What are the conditions for the total internal reflection to occur?
1) The light ray should go from a denser medium to a rarer medium.
2) The angle of incidence should be greater than the critical angle.
