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प्रश्न
Three convex lenses are available having focal lengths of 4 cm, 40 cm and 4 m respectively. Which one would you choose as a magnifying glass and why?
उत्तर
We will choose the lens with a focal length of 4 cm as the image formed will be more magnified (the smaller the focal length of a lens, the higher will be the magnification).
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संबंधित प्रश्न
A student focuses the image of a well-illuminated distant object on a screen using a convex lens. After that, he gradually moves the object towards the lens and each time focuses its image on the screen by adjusting the lens.
(i) In which direction, towards the screen or away from the screen, does he move the lens?
(ii) What happens to the size of the image? Does it decrease or increase?
(iii) What happens to the image on the screen when he moves the object very close to the lens?
A 1 cm high object is placed at a distance of 2f from a convex lens. What is the height of the image formed?
Draw a ray diagram to show the formation of a real magnified image by a convex lens. (In your sketch the position of object and image with respect to the principal focus of lens should be shown clearly).
What type of lens is shown in the diagram on the right? What will happen to the parallel rays of light? Show by completing the ray diagram.
What is the position of image when an object is placed at a distance of 10 cm from a convex lens of focal length 10 cm?
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 inverted and enlarged?
State two applications of a convex lens.
State the position of object, position of image, nature of image when: Convex lens is used as in searchlight.
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?
