Refraction and Lens Basics

A compilation of vocabulary related to refraction and lenses to aid in studying for exams on optics.

Refraction

The bending of light as it passes from one medium to another due to a change in velocity.

Index of Refraction

A measure of how much the speed of light is reduced in a medium compared to vacuum.

Snell's Law

A formula used to describe the relationship between the angle of incidence and angle of refraction; n1sin(θ1) = n2sin(θ2).

Converging Lens

A lens that bends light rays toward a single point, producing real or virtual images.

Focal Length (f)

The distance from the lens to the focal point where parallel rays of light converge.

Magnification (M)

The ratio of the height of the image to the height of the object.

Thin-Lens Equation

1/f = 1/p + 1/q, relating the focal length (f), object distance (p), and image distance (q) for lenses.

Total Internal Reflection

When light hits the boundary of a medium at an angle larger than the critical angle, it reflects entirely back into the medium.

Dispersion

The separation of light into its component wavelengths due to different indices of refraction for different wavelengths.

Virtual Image

An image formed by a lens or mirror that appears to be behind the lens or mirror and cannot be projected onto a screen.