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Question
How will you differentiate between a convex and a concave lens by looking at a distant object.
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Solution
On seeing a distant object through the lens, if its inverted image is seen, then the lens is convex, and if the upright image is seen, then the lens is concave.
RELATED QUESTIONS
Explain optical centre of a lens with the help of proper diagram(s).
In figure, (a) and (b), F1 and F2 are the two foci of thin lenses and AB is the incident ray. Complete the diagram to show the path of the ray AB after refraction through each lens.
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| (a) |
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| (b) |
A ray of light after refraction through a lens emerges parallel to the principal axis of the lens. The incident ray either passes through ______.
Distinguish between a real and a virtual image.
Fig shows an object PQ placed on the principle axis of a lens L. The two foci of the kens are F1 and f2. The image formed by the lens is erect, Virtual and dimnished.
(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.
Define the term focus of a lens.
How will you differentiate between a convex and a concave lens by looking at a printed page?
State the nature and position of the object on the principal axis to obtain a real and magnified image.
Complete the following diagram and state what happens to the ray of light after refraction through the lens.
Draw a ray diagram to show the image formed by a convex lens when the object is placed between F and 2F.
