Correct exposure for a photographic print is 10 seconds at a distance of one metre from a point source of 20 candela . For an equal fogging of the print placed at a distance of 2 m from a 16 candela source, the necessary time for exposure is

Correct exposure for a photographic print is 10 seconds at a distance

1.	Correct exposure for a photographic print is 10 seconds at a distance of one metre from a point source of 20 candela . For an equal fogging of the print placed at a distance of 2 m from a 16 candela source, the necessary time for exposure is
Answer» `100 sec` `25 sec` `50 sec` `75 sec` ANSWER :c

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Correct exposure for a photographic print is 10 seconds at a distance of one metre from a point source of 20 candela . For an equal fogging of the print placed at a distance of 2 m from a 16 candela source, the necessary time for exposure is

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