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| Numerical - 04 |
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| 04. A needle placed 45 cm from a lens forms an image on a screen placed 90 cm on the other side of the lens. Identify the type of lens and determine its focal length. What is the size of the image if the size of the needle is 5.0 cm? |
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| Suggested solution: |
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| u = -45 cm v = +90 cm, f = ? |
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| The lens is clearly a converging lens. |
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| The negative sign indicates that the image is inverted. |
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