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प्रश्न
When does a ray of light falling on a lens pass through it undeviated?
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उत्तर
A ray of light falling on the lens passes through it undeviated when it passes through the optical centre.
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संबंधित प्रश्न
What is a lens?
The diagram below shows a lens as a combination of a glass slab and two prisms.
- Name the lens formed by the combination.
- What is the line XX’ called?
- Complete the path of the incident ray AB after passing through the lens.
- The final emergent ray either meets XX’ at a point or appears to come from a point on XX’. Label it as F. What is this point called?
A ray of light after refraction through a lens emerges parallel to the principal axis of the lens. The incident ray either passes through ______.
A ray of light incident on a lens parallel to its principal axis, after refraction passes through or appears to come from ______.
Study the diagram shown in the following Figure.
Name the lens LL’ and draw its outline.
A ray of light incident parallel to the principal axis of a lens, passes undeviated after refraction.
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.
Fig. shows two rays of light Op and OQ coming from an object at the bottom of a pond, incident on the water surface.
(a) Mark on the diagram
(i) The angle of incidence of ray OP,
(ii) The angle of refraction of ray Op,
(iii) The position of image of the object as seen from above.
(iv) An approximate path of the ray OQ.
(b) Explain, why do the rays of light change directions on passing from water to air.
(c) A fish in water sees everything outside the water by rays of light entering its eye in a small cone of light. Draw a diagram and explain how does this happen.
How will you differentiate between a convex and a concave lens by looking at a distant object.
Complete the following diagram and state what happens to the ray of light after refraction through the lens.
