light

What is the definition of light?

Light is a form of energy that causes the sensation of vision.

What is rectilinear propagation of light?

The travel of light in a straight line in a homogenous medium.

Does light require a medium to travel?

No, light can travel through a vacuum.

What is the speed of light in a vacuum?

The speed of light in vacuum is c = 3 × 10⁸ m/s.

Define reflection of light.

The phenomenon in which a ray of light bounces back into the same medium after striking a smooth surface.

What are the two laws of reflection?

1. Angle of incidence (∠i) = Angle of reflection (∠r). 2. The incident ray, the reflected ray, and the normal lie in the same plane.

What is regular reflection?

When parallel incident rays reflect as parallel rays, typically seen with smooth and polished surfaces.

What is diffuse reflection?

When parallel rays reflect in different directions, typically seen with rough surfaces.

Define a spherical mirror.

A mirror whose reflecting surface is a part of a sphere.

What is a concave mirror?

A spherical mirror where the inner surface is reflecting and parallel rays converge after reflection.

What is a convex mirror?

A spherical mirror where the outer surface is reflecting and parallel rays diverge after reflection.

What is the focal length (f) of a spherical mirror?

The distance between the pole (P) and the focus (F), given by f = R/2.

Standard Rays for Spherical Mirrors

1. Parallel incident ray goes through focus (F). 2. Ray through focus (F) reflects parallel to principal axis. 3. Ray through center of curvature (C) returns along the same path. 4. Ray striking pole (P) reflects at the same angle as incidence.

What type of images does a concave mirror form?

Concave mirrors can form real/inverted or virtual/erect images depending on object distance.

Describe the image formed by a convex mirror.

Convex mirrors always form virtual, erect, and diminished images regardless of the object's distance.

What are some uses of concave mirrors?

Headlights, shaving mirrors, solar cookers, dentist's mirrors, microscopes, and telescopes.

What are some uses of convex mirrors?

Rear-view mirrors in vehicles and security mirrors in shops, ATMs, and parking lots.