Chapter 11-The production and reflection of light

What is the angle of incidence?

The angle between the incident ray and the normal.

What is the angle of reflection?

The angle between the reflected ray and the normal; equals the angle of incidence.

What is a concave (converging) mirror?

A mirror curved inward, focusing parallel rays to a point.

What is a convex (diverging) mirror?

A mirror curved outward, spreading parallel rays outward.

What is diffuse reflection?

Reflection from rough surfaces, scattering rays in multiple directions.

What is specular reflection?

Reflection from smooth surfaces, where rays stay parallel.

What is an incident ray?

The incoming light ray striking a surface.

What is a reflected ray?

The light ray bouncing off a reflective surface.

What is lateral inversion?

The left-right flipping of an image seen in a mirror.

What is a light ray?

A narrow beam representing the path of light.

What is the normal?

An imaginary line perpendicular to the surface at the point where light hits.

What is a plane mirror?

A flat mirror producing upright, virtual, same-size images.

What is a ray diagram?

A sketch showing how light rays reflect or refract, helping locate images.

What is a real image?

An image formed where light rays actually meet; can be projected.

What is a virtual image?

An image where rays appear to meet but don’t actually converge.

What are the two laws of reflection?

(1) Angle of incidence = angle of reflection; (2) rays + normal lie in the same plane.

What is needed for a surface to act as a mirror?

It must be smooth and polished to create specular reflection.

How does a plane mirror affect image S.A.L.T.?

Same size, Upright, Behind mirror, Virtual.

How many rays are needed to locate an image in a curved mirror?

At least two reflected rays.

What are the parts of a curved mirror diagram?

Principal axis, focal point, center of curvature, vertex, normal, rays.

What’s the difference between real and virtual images?

Real: rays meet, projectable; Virtual: rays appear to meet, not projectable.

What are the uses of plane mirrors?

General reflection, checking appearance, optical devices.

What are the uses of concave mirrors?

Magnifying mirrors, reflecting telescopes, flashlights.

What are the uses of convex mirrors?

Security mirrors, car side mirrors, wide-angle views.

What are the types of light emission?

Incandescence, electric discharge, fluorescence, phosphorescence, chemiluminescence, bioluminescence, triboluminescence, LED.

What is incandescence?

Light from heating an object (e.g., filament bulbs).

What is electric discharge?

Light produced when electric current passes through gas (e.g., neon lights).

What is fluorescence?

Immediate emission of light when exposed to UV (e.g., fluorescent lights).

What is phosphorescence?

Delayed light emission after absorbing UV (e.g., glow-in-the-dark).

What is chemiluminescence?

Light from a chemical reaction (e.g., glow sticks).

What is bioluminescence?

Light produced by living organisms (e.g., fireflies).

What is triboluminescence?

Light from scratching, crushing, or rubbing crystals (e.g., sugar cubes).

What is a light-emitting diode (LED)?

A device that emits light when current flows through semiconductors.

What is the speed of light?

~3 × 10⁸ m/s in a vacuum.

Where is light in the electromagnetic spectrum?

Between infrared and ultraviolet; the visible range we can see.

What is the composition of white light?

A mix of all visible wavelengths (ROYGBIV).

How is light transmitted?

As electromagnetic waves that can travel through space without a medium.

What is the center of curvature?

The center of the sphere from which a mirror segment is cut.

What is the focal point?

The point where parallel rays meet after reflecting or refracting.

What is the vertex (mirror)?

The point where the principal axis meets the mirror surface.