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Question
How will you differentiate between a convex and a concave lens by looking at a printed page?
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Solution
On keeping the lens near a printed page, if the letters appear magnified, then the lens is convex, and if the letters appear diminished, then the lens is concave.
RELATED QUESTIONS
State the condition when a lens is called an equi-convex or equi-concave.
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Study the diagram shown in Fig. 5.56
what are the two other characteristics of the image?
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(i) Draw the outline ofthe lens L used and Named it.
(ii) Draw a ray of light starting from Q and passing through O. show the same ray after refraction by the lens.
(iii) Draw another ray from Q Which is incident parallel to the principle axis and show how it emerges after refraction from the lens.
(iv) Locate the final image formed.
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(iv) An approximate path of the ray OQ.
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When does a ray of light falling on a lens pass through it undeviated?
