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Question
What is optical centre of a thin lens? Draw diagram/diagrams to illustrate it.
Solution
The optical centre of a thin lens is a point O on the principal axis of the lens such that a ray of light directed towards it, passes undeviated and undisplaced from the lens. The diagram illustrating it in a convex and a concave lens are shown alongside.
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RELATED QUESTIONS
A ray of light incident at a point on the principal axis of a convex lens passes undeviated through the lens.
- What special name is given to this point on the principal axis?
- Draw a labelled diagram to support your answer in part (a).
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- Draw a ray diagram to show it.
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To obtain a magnification of +2 with a concave mirror of radius of curvature 60 cm the object distance must be ______.
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