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Standard XII

Physics

f-R Relationship

A point sourc...

Question

A point source of light is 60 cm from a screen and is kept at the focus of a concave mirror which reflects light on the screen. The focal length of the mirror is 20 cm. The ratio of average intensities of the illumination on the screen when the mirror is present and when the mirror is removed is

36 :1

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37 :1

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49 :1

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10 :1

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Solution

The correct option is D 10 :1
Option D is correct

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A point source of light is 60 cm from a screen and is kept at the focus of a concave mirror which reflects light on the screen. The focal length of the mirror is 20 cm. The ratio of average intensities of the illumination on the screen when the mirror is present and when the mirror is removed is

The correct option is D 10 :1Option D is correct

The correct option is D 10 :1
Option D is correct