REFRACTION THROUGH CURVED SURFACES (INTRODUCTION)

BEHAVIOUR OF LIGHT WHEN IT ENTERS FROM ONE MEDIUM TO ANOTHER THROUGH CURVED SURFACES

Let us try to understand how to draw ray diagrams in case of curved surfaces.

We know that a ray of light passing from rarer to denser medium bends towards normal and bends away to normal when it is passing from denser to rarer medium.

So it is important to draw a normal to the curved surface.

Any line drawn from centre of curvature to a point on the surface acts like a normal to that surface because it makes an angle of 90⁰ with the tangent drawn to that surface.

Observe some examples of refraction of light through curved surfaces.

Consider blue shaded region as denser medium.

1)1) The ray passing from rarer medium to denser medium bends towards normal.

1)2) The ray passing from denser to rarer medium bends away to normal.

1)3) The ray passing along the normal(through centre of curvature) will not deviate from its original path.

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