The proper exposure time for a photographic print is 20 s at a distance of 0.6 m from a 40 candle power lamp. How long will you expose the same print at a distance of 1.2 m from a 20 candle power lamp ?

The proper exposure time for a photographic print is 20 s at a distance of 0.6 m from a 40 candles power lamb.How long will you expose the same print at a distance of 1.2 m from a 20 candles power lamb?

The proper exposure time for a photographic print is 20 s at a distance of 0.6 m from a 40 candles power lamb.How long will you expose the same print at a distance of 1.2 m from a 20 candles power lamb?

The proper expsoure time for a photographic print is 20s at a distance of 0.6m froma 40 candles power lamb.How long will you expose the same print at a distance of 1.2m form a 20 candles power lamb?

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

A satisfactory photographic print is obtained when the exposure time is 10 sec at a distance of 2m from a 60 cd lamp. The time of exposure required for the same quality print at a distance of 4m from a 120 cd lamp is