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| Numerical - 07 |
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| 07. A glass lens has a focal length of 5 cm in air. What will be its focal length in water? Refractive index of glass is 1.51 and that of water is 1.33. |
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| If fa be the focal length of glass lens in air, then |
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| If fw be the focal length of a glass lens in water, then |
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