Light – Reflection and Refraction

Flashcards covering key vocabulary related to light reflection and refraction, spherical mirrors, lenses, and related concepts, based on the provided lecture notes.

Diffraction of Light

The effect when an opaque object on the path of light becomes very small, causing light to bend around it instead of traveling in a straight line.

Concave Mirror

A spherical mirror whose reflecting surface is curved inwards, facing towards the center of the sphere.

Convex Mirror

A spherical mirror whose reflecting surface is curved outwards.

Pole (P)

The center of the reflecting surface of a spherical mirror.

Center of Curvature (C)

The center of the sphere of which the reflecting surface of a spherical mirror forms a part.

Radius of Curvature (R)

The radius of the sphere of which the reflecting surface of a spherical mirror forms a part.

Principal Axis

A straight line passing through the pole and the center of curvature of a spherical mirror.

Principal Focus (F) of a Concave Mirror

The point on the principal axis where rays parallel to the principal axis converge after reflection from a concave mirror.

Principal Focus (F) of a Convex Mirror

The point on the principal axis from which rays parallel to the principal axis appear to diverge after reflection from a convex mirror.

Focal Length (f)

The distance between the pole and the principal focus of a spherical mirror.

Aperture

The diameter of the reflecting surface of a spherical mirror.

Refraction of Light

The bending of light as it passes obliquely from one transparent medium to another.

Incident Ray

The ray that strikes the surface.

Refracted Ray

The light ray after refraction

Emergent Ray

The ray that emerges from a refracting surface.

Snell’s Law of Refraction

The ratio of the sine of the angle of incidence to the sine of the angle of refraction, which is a constant for a given pair of media.

Refractive Index (n21)

The ratio of the speed of light in medium 1 to the speed of light in medium 2.

Absolute Refractive Index

Refractive index of a medium with respect to vacuum.

Lens

A transparent material bound by two surfaces, of which one or both surfaces are spherical.

Convex Lens (Converging Lens)

A lens with two spherical surfaces bulging outwards, thicker at the middle, and converges light rays.

Concave Lens (Diverging Lens)

A lens bounded by two spherical surfaces curved inwards, thicker at the edges, and diverges light rays.

Centers of Curvature (C1, C2)

The centers of the spheres of which the surfaces of a lens form a part.

Principal Axis (Lens)

An imaginary straight line passing through the two centers of curvature of a lens.

Optical Centre (O)

The central point of a lens through which a ray of light passes without any deviation.

Aperture (Lens)

The effective diameter of the circular outline of a spherical lens.

Principal Focus (F) of a Convex Lens

The point on the principal axis where rays parallel to the principal axis converge after refraction from a convex lens.

Principal Focus (F) of a Concave Lens

The point on the principal axis from which rays parallel to the principal axis appear to diverge after refraction from a concave lens.

Focal Length (f) of a Lens

The distance of the principal focus from the optical centre of a lens.

Power of a Lens (P)

The degree of convergence or divergence of light rays achieved by a lens.

Dioptre (D)

The SI unit of power of a lens, equal to the power of a lens with a focal length of 1 meter.