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प्रश्न
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उत्तर
Focal length is the distance measured from the optical centre to the focus. The symbol for it is f.
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संबंधित प्रश्न
Study the diagram shown in Fig. 5.56
what are the two other characteristics of the image?
The diagram given below shows the position of an object OA in relation to a converging lens L whose foci are at F1 and F2.
- Draw two rays to locate the position of the image.
- State the position of the image with reference to the lens.
- Describe three characteristics of the image.
- Describe how the distance of the image from the lens and its size change as the object is moved towards F1.
State the condition of the following:
A lens has both its focal lengths equal.
What type of lenses are used in spectacles worn by an old lady for knitting?
In the following diagram , the object and the image formed by the respective lenses are shown. Complete the ray diagram, and locate the focus. Find the focal length of the lens.
How will you differentiate between a convex and a concave lens by looking at a distant object.
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.
When does a ray of light falling on a lens pass through it undeviated?
Complete the following diagram and state what happens to the ray of light after refraction through the lens.
