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प्रश्न
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.
उत्तर
Following are the precautions while making the image by the help of convex lens:
1) Fix the convex lens vertically in the lens holder.
2) The base of the lens and white screen should be in a line with the measuring scale.
3) Record the position of the lens and screen only when a well-defined sharp image is formed.
4) There should not be an obstacle in the path of the convex lens.
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संबंधित प्रश्न
How could you find the focal length of a convex lens rapidly but approximately?
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.
Rewrite the image distances in the correct order.
The focal lengths of four convex lenses P, Q, R and S are 20 cm, 15 cm, 5 cm and 10 cm, respectively. The lens having greatest power is :
(a) P
(b) Q
(c) R
(d) S
The given below figure shows an object OA and its image IB formed by a lens.
Out of the five incident rays shown in the figure find the three rays that are obeying the laws of refraction and may be used for locating the position of image formed by a convex lens:
(A) 1, 2 and 3
(B) 2, 3 and 4
(C) 3, 4 and 5
(D) 1, 2 and 4
(a) What type of a lens can be used as a magnifying glass?
(b) Show by a ray diagram the formation of a real image by simple magnifying lens.
How will you decide whether a given piece of glass is a concave lens, convex lens, or a plane glass plate?
State the nature and position of the object on the principal axis to obtain a virtual and magnified image.
Write the name.
The lens used in simple microscope.
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?
