Measurement of optical absorption of a solution is disturbed by the additional stray light falling at
the photo-detector. For estimation of the error caused by stray light the following data could be
obtained from controlled experiments. Photo-detector output without solution and without stray light is 500 μW. Photo-detector output without solution and with stray light is 600 μW. Photo-detector output with solution and with stray light is 200 μW. The percent error in computing absorption coefficient due to stray light is