InterviewSolution
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InterviewSolution
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an object with the height of 6 cm is placed in the front of concave lens of focal length 20 cm is placed at a distance of 30cm find nature size and position the image and also draw the diagram |
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Answer» n:-Height of the object (ho)= 6 cm FOCAL length(f) = - 20 cm Object distance(u) = - 30 cm ( Always measured from the optical center ) By using lens formula ,➽ 1 / f = 1 / v - 1 / u On rearranging ,➽ 1 / v = 1 / f - 1 / u ➽ 1 / v = 1 / - 20 + 1 / 30 ➽ 1 / v = - 3 + 2 / 60 ➽ 1 / v = - 1 / 60 ➽ v = - 60 cm The image is formed at a distance of 60 cm from the optical center on the same SIDE as that of the object We know that ,➽ m = v / u = HI / ho ➽ hi = v x ho / u ➽ hi = - 60 x 6 / - 30 ➽ hi = 12 cm The image formed is enlarged , erect and virtual |
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