Physics: Light-Reflection and Refraction

reflection

reflection

phenomenon of light ray incident on a reflective/polished surface, bouncing back.

Light travels through three types, which are

wave, straight line and matter

Type of reflections (straight line)

1. Reflection

2. Refraction

3. Dispersion

4. Scattering

Characteristics of image formed by a plane mirror

1. Distance from the object and mirror is equal to the distance between the image formed and the mirror (u=v)

2. Size of the object is the same as the same of the image formed.(ho=hi)

3. The image formed in laterally inverted from the object

4. The image formed is virtual (image cannot be captured on screen) and erect (same nothing changed)

Spherical Mirror Definition

spherical mirrors are the reflecting surface which is a part of a sphere

Two types of spherical mirrors

1. Concave

2. Convex

Concave mirror and Convex mirror

Concave: The reflecting surface is curved inwards

Convex: The reflecting surface is curved outwards

Terms related to spherical mirror.

explain

Pole (P)

Centre of reflecting surface of a spherical mirror

Centre of curvature (C)

The reflecting surface is part of a sphere, the centre of this sphere is called the centre of curvature

Radius (R)

The distance between the centre of curvature to the pole

Principal Axis

The straight line passing through the centre of curvature and the pole

Principal Focus (F)

The point where all the reflected rays intersect on the principal axis

Focal length (f)

The distance between principal focus and the pole

Aperture

diameter of the reflected surface

Relation between R and f

2f=R

2 laws of reflection

1. The angle of incidence is same as the angle of reflection

2. The incident ray, normal and the reflected ray all lie on the same plane

Rules of image formation in a spherical mirror

There are 4 rules and each applies to convex and concave mirrors.

Rule 1 (Concave)

An incident ray parallel to the principal axis, after reflection will pass through the principal focus

Rule 2 (Concave)

An incident ray passing through the principal focus, after reflection, will be parallel to the principal axis

Rule 2 (Convex)

An incident ray which is directed at the principal focus, after reflection will be parallel to the principal axis

Rule 3 (Concave)

An incident ray passing through the centre of curvature, will reflect back in the same path

Rule 3 (Convex)

An incident directed at the centre of curvature will reflect back in the same path

Rule 4 (both)

Any incident ray on a spherical mirror wil