Topic 14 - Light Flashcards
What is the angle of incidence?
Angle between the incident ray and the normal line.
What is the angle of reflection?
Angle between the reflected ray and the normal line.
What is a concave lens?
A lens that makes parallel rays diverge.
What is a convex lens?
A lens that makes light rays parallel to the principal axis converge at a point.
What is diffuse reflection?
Reflection from a rough surface and thus the light rays are scattered in different directions.
What is the focal length?
The distance from the centre of a lens to the point where light rays parallel to the principal axis are focused, or in a divergent lens, diverge from.
What is the equation for magnification?
The image height / the object height.
What is the normal?
A straight line through a surface or boundary perpendicular to the surface or boundary.
What is an opaque object?
An object that light cannot pass through.
What is the principal focus?
The point where light rays parallel to the principal axis of a lens are focused, or in a diverging lens, divert from.
What is a real image?
An image formed by a lens that can be projected onto a screen.
What is refraction?
The change of direction of a light ray when it passes across a boundary between two transparent substances.
What is specular reflection?
Reflection from a smooth surface. Each light ray is reflected in a single direction.
What is a translucent object?
An object that allows light to pass through, but the light is scattered or refracted.
What is a transparent object?
An object that transmits all the incident light that enters the object.
What is a virtual image?
An image, seen in a lens or mirror, from which light rays appear to come after being refracted by a lens or reflected by a mirror.
What is the law of reflection?
On reflection from a smooth surface, the angle of the reflected ray is equal to the angle of the incident ray.