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प्रश्न
Simple microscope : Number of convex lens one : : compound microscope : _______
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उत्तर
Simple microscope : Number of convex lens one : : compound microscope : Number of convex lenses two
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संबंधित प्रश्न
A student places a candle flame at a distance of about 60 cm from a convex lens of focal length 10 cm and focuses the image of the flame on a screen. After that he gradually moves the flame towards the lens and each time focuses the image on the screen.
(a) In which direction-toward or away from the lens, does he move the screen to focus the image?
(b) How does the size of the image change?
(c) How does the intensity of the image change as the flame moves towards the lens?
(d) Approximately for what distance between the flame and the lens, the image formed on the screen is inverted and of the same size?
Study the given ray diagrams and select the correct statement from the following:
(A) Device X is a concave mirror and device Y is a convex lens, whose focal lengths are 20 cm and 25 cm respectively.
(B) Device X is a convex lens and device Y is a concave mirror, whose focal lengths are 10 cm and 25 cm respectively.
(C) Device X is a concave lens and device Y is a convex mirror, whose focal lengths are 20 cm and 25 cm respectively.
(D) Device X is a convex lens and device Y is a concave mirror, whose focal lengths are 20 cm and 25 cm respectively.
An object is placed at a distance of 15 cm from a concave lens of focal length 30 cm. List four characteristics (nature, position, etc.) of the image formed by the lens.
A convex lens of focal length 8 cm forms a real image of the same size as the object. The distance between object and its image will be:
(a) 8 cm
(b) 16 cm
(c) 24 cm
(d) 32 cm
An object 3 cm high is placed 24 cm away from a convex lens of focal length 8 cm. Find by calculations, the position, height and nature of the image.
Show by a diagram the refraction of two light rays incident parallel to the principal axis on a convex lens by treating it as a combination of a glass slab and two triangular glass prisms.
A convex lens forms an image of an object equal to the size of the object. Draw a diagram to illustrate it.
In the following cases, where must an object be placed in front of a convex lens so that the image formed is at infinity?
Where should an object be placed in front of a convex lens to get a real image of the size of the object?
An object 4.0 cm in size, is placed 25.0 cm in front of a concave mirror of focal length 15.0 cm.
(i) At what distance from the mirror should a screen be placed in order to obtain a sharp image?
(ii) Find the size of the image.
(iii) Draw a ray diagram to show the formation of the image in this case.
How will you decide whether a given piece of glass is a concave lens, convex lens, or a plane glass plate?
What happens to the image formed by a convex lens if its lower part is blackened?
In sunglasses, both of its surfaces are curved, yet their behaviour is neither like a convex lens nor like a concave lens. State the reason.
Draw a diagram to show the convergent action of a convex lens by treating it as a combination of glass block and two triangular glass prisms, with the aid of two parallel incident rays.
An object is placed in front of a convex lens such that the image formed has the same size as that of the object. Draw a ray diagram to illustrate this.
Can one bum a piece of paper in daylight by just using a convex lens instead of a match or any direct flame? Support your answer with the help of an appropriate ray diagram.
A convex lens of focal length 20 cm can produce a magnified virtual as well as real image. Is this a correct statement? If yes, where shall the object be placed in each case for obtaining these images?
Distinguish between:
Concave lens and Convex lens
