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प्रश्न
State the sign convention to measure the distances for a lens.
उत्तर
- Every distance is measured starting at the optical centre.
- The object should be positioned to the left of the lens. It measures the object's distance, i.e., u.
- f stands for the second focus, also known as the focal length, and v stands for the image distance.
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Distances measured with respect to the incoming ray's direction are recorded as positive, while those measured in its opposite direction are recorded as negative. That is, distances marked as +ve to the right and -ve to the left of the lens.
- +ve and -ve stand for height or length above the major axis, respectively.
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संबंधित प्रश्न
Draw ray diagrams to show the formation of three times magnified (a) real, and (b) virtual image of an object by a converging lens. Mark the positions of O, F and 2F in each diagram.
If the image formed by a lens for all positions of the object placed in front of it is always virtual, erect and diminished, state the type of the lens. Draw a ray diagram in support of your answer. If the numerical value of focal length of such a lens is 20 cm, find its power in new cartesian sign conventions.
An object 5 cm high is held 25 cm away from a converging lens of focal length 10 cm.
(i) Draw the ray diagram and
(ii) Calculate the position and size of the image formed.
(iii) What is the nature of the image?
All distances parallel to the principal axis are measured from the _______.
Write an Explanation.
Magnification
Linear magnification (m) produced by a concave lens is ______.
