Light: Reflection and Refraction

Flashcards for CBSE Class 10 Science Chapter 10 Light: Reflection and Refraction Notes

Light

Light is electromagnetic radiation visible to the human eye, behaving as both a wave and a particle. Essential for vision and photosynthesis.

Nature of Light

Light can act as a ray, wave, or particle depending on the circumstances.

Rectilinear propagation of light

Light travels in straight lines between two points.

Fermat’s Principle

Light takes the quickest path between two points, which may not be the shortest.

Plane mirror

Flat, polished surface with minimal irregularities that reflects light.

Characteristics of images

Images can be real or virtual, erect or inverted, magnified or diminished.

Principle of Reversibility of light

If reflected light's direction is reversed, it retraces its path.

Spherical mirror

Curved mirror from a hollow sphere with a reflective inner surface and coated outer surface.

Relationship between focus and radius of curvature

Focal length (F) is half the radius of curvature (R): F = R/2

Curved Mirror

Mirror with a curvature.

Pole (P)

Midpoint of a spherical mirror.

Centre of curvature (C)

Reflecting surface of a spherical mirror forms a part of sphere.

Radius of curvature (r)

Distance between the center of curvature and the spherical mirror.

Principal Axis

Line through the pole and the center of curvature.

Concave Mirror

Spherical mirror with an inward-bulging reflecting surface.

Convex Mirror

Spherical mirror with an outward-bulging reflecting surface.

Focus (F)

Point where rays parallel to the principal axis converge (concave) or appear to diverge from (convex).

Focal length

Distance between the pole and the focus of a spherical mirror.

Magnification

Ratio of image height to object height.

Refraction

Bending of light as it passes through a different medium.

Relative Refractive Index

Refractive index of a medium relative to another.

Refractive Index

Degree to which light bends when entering a new medium.

Critical angle

Incident angle at which the refracted ray travels along the surface between two media.

Total Internal Reflection

Reflection within a denser medium when the incident angle exceeds the critical angle.

Spherical lenses

Lenses formed by binding two spherical transparent surfaces.

Convex lenses (Converging lens)

Lenses formed by two outward-bulging spherical surfaces; converges light rays.

Concave lenses (Diverging lens)

Lenses formed by two inward-curved spherical surfaces; diverges light rays.

Pole (P)

Midpoint or symmetric center of a spherical lens, also known as Optical Centre.

Principal Axis of Lens

Line through the optical center and the center of curvature of a lens.

Paraxial Ray

Ray close to and parallel to the principal axis.

Focus (F)

Point where parallel light rays converge or appear to diverge after refraction through a lens.

Power of a Lens

The reciprocal of the focal length of a lens in meters: 1/f