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Light — Science STD 7 — Question

Gujarat BoardEnglish MediumSTD 7ScienceLight3 Marks
Question
A student is asked to focus sunlight using two different lenses onto a paper.
Image

Observe the image carefully and answer the following questions.
(i) State the name for the shape of lenses X and Y.
(ii) Which of these two lenses can be used to magnify images?
(iii) Explain the changes that happen to the paper kept under both the lenses.
✓

Answer

(i) Lens X → Concave
Lens Y → Convex
(ii) Lens Y is convex in nature. Hence, it can be used to magnify images.
(iii) The paper under lens X will remain as it is. But in case of lens Y, due to its converging nature, the sun rays will be focussed at a point. Ultimately, the paper will start burning.

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