Explain an Activity to find the Normal to a Curved Surfaces? Write in Detail with a neat labelled diagram.
Answers
Answer:
The Diagram or Image is in the Attachment!
(i) Take a small piece of thin foam or rubber.
(ii) Put some pins in a straight line on the foam.
(iii) All these pins are perpendicular to the foam.
(iv) If the foam was considered as a mirror, each pin would represent the normal at the point.
(v) Any ray incident at the point where the pin makes contact with the surface will reflect at the same angle the incident ray made with the pin - normal.
(vi) Now bend the foam piece inwards.
(vii) If we bend the foam piece Outwards, the Pins seem to move away from each other.
(viii) This gives us an Idea about Spherical Mirror.
(ix) A Concave mirror will be like the rubber sole bent inwards and the Convex mirror will be like the rubber sole bent Outwards.
(x) For a Concave Mirror, like these pins all Normal will converge towards a point. This point is call “Center of Curvature” of the mirror.
(xi) For the ray R, the Incident angle is the angle made with the Radius (Normal) is <i and the reflected angle is <r. We know by First law of Relfection which states '<i = <r (Angle of Incidence = Angle of Reflection)'.
