Optics: Reflection and Refraction

Vocabulary-style flashcards covering the principles of reflection, mirror properties, magnification sign conventions, refraction, and Snell's Law.

Regular Reflection

The process where smooth, shiny surfaces like calm water, mirrors, glass, or polished metal create clear images.

Image

A copy of an object made by a mirror or optical device.

Incident Ray

The light going towards the mirror.

Reflected Ray

The light coming away from the mirror.

Normal

An imaginary line perpendicular to the mirror surface used to measure angles.

Law of Reflection

The rule stating that the angle of incidence is equal to the angle of reflection ($i = r$).

Plane Mirror

A mirror with a flat surface that produces an upright, same-sized, and virtual image.

Virtual Image

An image formed by rays that do not actually come from the image location; light only appears to come from behind the mirror and cannot be seen on a screen.

Lateral Inversion

The side-to-side flipping (left-right reversal) observed in images formed by a plane mirror.

SALT

An acronym used to predict image properties in a plane mirror: Size (same), Alignment (upright/laterally reversed), Location (behind mirror/same distance), and Type (virtual).

Real Image

An image formed when light rays actually meet (converge), which can be projected onto paper or a screen.

Focal Point

The point where reflected light rays meet (for converging mirrors) or appear to originate from (for diverging mirrors).

Vertex

The center point of a mirror surface.

Principal Axis

The imaginary line passing through the vertex of the mirror.

Focal Length

The distance from the focal point to the vertex of the mirror.

Concave Mirror

Also called a converging mirror, it curves inward like a bowl and reflects light to a single point.

Convex Mirror

Also called a diverging mirror, it curves outward and spreads out light rays, always producing a virtual, upright, and smaller image.

Magnification ($M$)

A measure of how much bigger or smaller an image is compared to the object, defined as $M = \frac{h_i}{h_o}$ or $M = -\frac{d_i}{d_o}$.

GRASP Method

A problem-solving strategy including Given, Required, Analysis, Substitute/Solve, and Paraphrase.

Refraction

The bending of light as it moves from one medium to another because the speed of light changes.

Index of Refraction ($n$)

A measure of how much a material slows down light, calculated as $n = \frac{c}{v}$ (speed of light in vacuum divided by speed of light in medium).

Critical Angle

The specific angle of incidence that results in a refracted angle of $90^\text{o}$.

Total Internal Reflection (TIR)

A phenomenon that occurs when light travels from a slower medium to a faster medium and the angle of incidence is larger than the critical angle, causing light to reflect back inside the medium.

Snell's Law

The exact relationship between the angle of incidence and angle of refraction, expressed as $n_1 \text{sin}(\theta_1) = n_2 \text{sin}(\theta_2)$.