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प्रश्न
Make the rrect choices in the following items :
An object is placed 50 cm from a connverging lens of focal length 30 cm. The image produced would be
पर्याय
lnverted and same size as the obíect
lnverted and diminished
lnverted and magnified
Erect and diminished
Erect and magnified
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उत्तर
lnverted and magnified
APPEARS IN
संबंधित प्रश्न
State the condition when a lens is called an equi-convex or equi-concave.
In the following figure (a) and (b), F1 and F2 are positions of the two foci of thin lenses. Draw the path taken by the light ray AB after it emerges from each lens.
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| (a) |
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| (b) |
Distinguish between a real and a virtual image.
State the condition of the following:
A ray passes undeviated through the lens.
What type of lenses are used in spectacles worn by an old lady for knitting?
Make the correct choices in the following items:
lf the image can be focused on a screen it must be
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.
(a)A ray of light is incident at 45° on the face of
(i) A rectangular block of glass.
(ii) A 600 glass prism.
(b) Draw a sketch showing how the ray of monochromatic ray of light passes through glass in each case.
(c) With the aid of a diagram, explain how the face of a right angled prism may totally reflect incident on it.
(d) A thick plane mirror produces several faint images in addition to a prominent one. Draw a ray diagram showing how reflection and refraction produce all these images.
(e) Fig. represents a stone S at the bottom of a pond of water. Using the two rays, as shown, complete the ray diagram to show where the image of the stone appears when viewed from E.
(f) What is a''mirage'? Explain with the help of a diagram.
(g) A man observes the bottom of a swimming pool of 3 m depth. If the refractive index of water is 1.3, what is the apparent depth of water?
(h) When a ray of light undergoes refraction through a glass slab and when it emerges it is displaced laterally (Fig). What are the factors on which the lateral displacement depends?
(i) Fig. shows three rays of light OA, OB and OC passing from water to air, making angles 490, 410 and 350 with the horizontal surface respectively. Draw an approximate path of the emergent ray for each. (Critical angle of water is 490.)
How will you differentiate between a convex and a concave lens by looking at a printed page?
