Light energy

Light

A form of energy that produces the sensation of sight.

Velocity of light in vacuum

300,000 km per second or 3 x 10^8 m/s.

Refraction of Light

The change in path of light when it passes from one medium to another due to a change in speed.

Angle of Incidence

The angle which the incident ray makes with the normal.

Angle of Refraction

The angle which the refracted ray makes with the normal.

Snell's Law

The law stating that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant.

Refractive Index

A measure of how much light slows down in a medium compared to air.

Effect of Refraction

An effect where objects like coins in water appear raised or bent due to light refraction.

Dispersion of Light

The splitting of white light into seven colors.

VIBGYOR

The acronym for the colors of the visible spectrum: Violet, Indigo, Blue, Green, Yellow, Orange, Red.

Mirage

An optical phenomenon in deserts caused by the refraction of light.

Apparent Depth

The depth perceived due to the refraction of light as it passes from water to air.

Real Depth

The actual depth of an object under water.

Sine Ratio

In Snell's law, the ratio of the sine of angle of incidence to angle of refraction.

Early Sunrise

Occurs when the sun rises above the horizon earlier in the morning.

Late Sunset

Occurs when the sun sets below the horizon later in the evening.

Refraction through a Rectangular Glass Block

The bending of light as it passes from air into the glass and back to air.

Normal Line in Refraction

An imaginary line perpendicular to the surface at the point of incidence.

Refraction through a Prism

The bending of light as it passes through a prism, caused by a change in speed when entering and exiting the material.

Angle of Deviation

The angle between the incident ray and the refracted ray after passing through the prism.

Spherical Mirror

A mirror with a reflecting surface that is part of a hollow sphere of glass or plastic.

Concave Mirror

A mirror that curves inward, causing light rays that strike it to converge.

Convex Mirror

A mirror that curves outward, causing light rays that strike it to diverge, providing a wider field of view.

Centre of Curvature

The center point of a sphere from which a spherical mirror or lens is derived; it is equidistant from all points on the reflecting or refracting surface.

Radius of Curvature

The distance from the center of curvature to the surface of a spherical mirror or lens; it determines the mirror's or lens's curvature.

Principle Axis

An imaginary line that passes through the center of curvature and the optical center of a mirror or lens, serving as a reference for measuring angles of reflection and incidence.

Focal Point

The point where parallel rays of light converge after passing through a lens or reflecting off a mirror.

Focal Length

The distance from the lens or mirror to its focal point, determining how strongly the lens or mirror converges or diverges light.