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प्रश्न
Define the term focus of a lens.
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उत्तर
The focus of a lens (often called the principal focus) is a specific point on its principal axis where light rays parallel to the axis either converge or appear to originate from after passing through the lens.
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संबंधित प्रश्न
What is a lens?
State the condition when a lens is called an equi-convex or equi-concave.
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) |
Study the diagram shown in Fig. 5.56
Complete the diagram to show the formation of image A’B’ of the object AB of same size.
Study the diagram shown in Fig. 5.56
where is the object located?
The diagram given below shows the position of an object OA in relation to a converging lens whose foci are at F1 and F2.
Describe three characteristic of the 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.
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.
Complete the following diagram and state what happens to the ray of light after refraction through the lens.
