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प्रश्न
_______ times larger images can be obtained by using a simple microscope.
पर्याय
5
10
20
60
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उत्तर
20 times larger images can be obtained by using a simple microscope.
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संबंधित प्रश्न
A student wants to project the image of a candle flame on the walls of school laboratory by using a lens:-
(a) Which type of lens should be use and why?
(b) At what distance in terms of focal length 'F' of the lens should be place the candle flame so as to get (i) a magnified, and (ii) a diminished image respectively on the wall?
(c) Draw ray diagram to show the formation of the image in each case?
Where should an object be placed so that a real and inverted image of the same size as the object is obtained using a convex lens?
Draw a ray diagram to show the formation of the image of an object be placed so that a real and inverted image of the same size as the object is obtained using a convex lens
An object is placed at a distance of 12 cm from a convex lens of focal length 8 cm. Find :
1) the position of the image
2) nature of the image
Where should an object be placed in order to use a convex lens as a magnifying glass?
What is a lens?
A convex lens of focal length 6 cm is held 4 cm from a newspaper which has print 0.5 cm high. By calculation, determine the size and nature of the image produced.
A student did an experiment with a convex lens. He put an object at different distances 25 cm, 30 cm, 40 cm, 60 cm and 120 cm from the lens. In each case he measured the distance of the image from the lens. His results were 100 cm, 24 cm, 60 cm, 30 cm and 40 cm, respectively. Unfortunately his results are written in wrong order.
What is the focal length of this lens?
A camera fitted with a lens of focal length 50 mm is being used to photograph a flower that is 5 cm in diameter. The flower is placed 20 cm in front of the camera lens.
At what distance from the film should the lens be adjusted to obtain a sharp image of the flower?
A teacher sets up the stand carrying a convex lens of focal length 15 cm at 42.7 cm mark on the optical bench. He asks four students A, B, C and D to suggest the position of screen on the optical bench so that a distinct image of a distant tree is obtained almost immediately on it. The positions suggested by the students were as
A. 12.7 cm
B. 29.7 cm
C. 57.7 cm
D. 72.7 cm
The correct position of the screen was suggested by
(a) A
(b) B
(c) C
(d) D
For which position of the object does a convex lens form a virtual and erect image? Explain with the help of a ray diagram.
Answer the following question.
List four precautions which a student should observe while determining the focal length of a given convex lens by obtaining an image of a distant object on a screen.
State the position of object, position of image, nature of image when: Convex lens is used as in searchlight.
Why do we say that the ‘2F’ and ‘F’ points of a convex lens can be regarded as a sort of ‘turning points’ as far as the nature of the image formed by it is concerned?
Object at 2F1 of a convex lens : Image at 2F2 : : Object at F1 : _______
: Object near the lens : : ______ : 
Which of the following statements is true?
Which of the following statements is true?
Distinguish between:
Concave lens and Convex lens
