Optics

Let us consider two lenses A anb B of focal length f₁ and f₂ placed in contact with each other. Let the object be placed at a point O beyond the focus of the first lens A. The first lens produces an image at I₁ is real, it serves as a virtual object for the […]

Refraction of light at a convex surface :- 1. For real image :- The figure shows the geometry of formation of image I of an object O on the principal axis of a spherical surface ( convex ) with centre of curvature C and radius of curvature R. The rays are incident from a medium

Twinkling of stars :- it is is a phenomenon of atmospheric refraction. Stars do not really twinkle they just appear to twinkle when seen from the surface of the earth. The star twinkling in the night because of the effect of our atmosphere. when starling enters our atmosphere it is affected by winds in the

Total internal reflection :- when light travels from and optically denser medium to rarer medium at the interface, it is partly reflected back into the same medium and partly refracted to the second medium, this reflection is called the internal reflection. Conditions for the total internal reflection :- Critical angle ( Ic ) :- The

Refraction of light :- when a beam of light encounters another transparent medium, a part of light gets reflected back into first medium while the rest enters the other, The direction of propagation of incident ray of light that enters the other medium changes at the interface of the two media. This phenomenon is called

The mirror equation :- The ray diagram shows the image A’B’ of an object AB formed by a concave mirror . We derive the mirror equation or the relation between the object distance (u), image distance (v) and the focal length (f). From the above figure the two right angle triangle A’B’F and MPF are

Consider a ray parallel to the principal axis strinking the mirror at M, CM will be perpendicular to the mirror at M. Let θ be the angle of incidence and MQ be the perpendicular from M on the principal axis, then ∠MCP = θ and ∠MFP =2θ Now tanθ =MQ/CQ and tan2θ = MQ/FQ for

Definitions regarding spherical mirrors. Pole :- The geometric centre of a spherical mirror is called its pole. Denoted by ‘P’ Principal axis :- The line joining the pole and centre of curvature of the spherical mirror is known as the principal axis. Centre of curvature :- the point in the centre of the sphere from

Reflection of light :- It is the change in direction of a light at an interface between two different media so that the light returns into the medium from which it originated. Laws of reflection of light :- When a ray of light is reflected from a smooth surface then These laws are valid at