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In Bunsen's grease spot photometer, ligh...

In Bunsen's grease spot photometer, light from a lamp with dirty chimney is exactly balanced by that of a candle distant 10 cm from the spot. When the chimney is cleaned, the candle has to be shifted by 2 cm to obtain the balance. Calculate the percentage of light absorbed by dirty chimney.

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The correct Answer is:
`30.55%`
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SL ARORA-RAY OPTICS-Problems For Self Practice
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  2. A lamp is hanging at a height of 4 m above a table. The lamp is lowere...

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  3. In Bunsen's grease spot photometer, light from a lamp with dirty chimn...

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  4. An electric bulb illuminates a plane surface. The intensity of illumin...

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  5. A lamp is hanging along the axis of a circular table of radius r. at w...

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  12. rays of light strike a horizontal plane mirror at an angle of 45^(@). ...

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  13. Two plane mirrors are inclined at angle theta as shown in figure. If a...

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  14. An object 0.04 m high is placed at a distance of 0.8 m from a concave ...

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  15. Find the size, nature and position of image formed by a concave mirror...

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  16. An object is placed in front of a concave mirror of radius of curvatur...

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  17. An object is placed at a distance of 15 cm from a convex mirror and im...

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  18. A convex mirror and a concave mirror of radius 10cm each are placed 15...

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  19. A candle flame 2 cm high is palced at distance of 2 metere from a wall...

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  20. A dentist concave mirror has a radius of curvature of 30 cm. How far ...

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