Passage II
A hologram is a three-dimensional image produced when light from a laser shines on a film coated with a material called a holographic emulsion. The laser provides the light at a specific wavelength.
The figure below shows the light energy per unit area (in ergs/cm2) required to create a hologram on 3 different emulsions using gas lasers. For example, an Ar laser must produce 100 ergs/cm2 to create a hologram on Emulsion 2. The figure also shows how the sensitivity to light of each emulsion and the light energy per unit area required to create a hologram on each emulsion vary with the wavelength of light used.
11. A new laser produces most of its light at 575 nm. According to the figure, to produce a hologram on Emulsion 1, how much light energy per unit area will the new laser have to produce?
Your Answer is
Correct Answer is B
Explanation
Look at the picture, corresponding to the Emulsion 1 curve, when the abscissa is 575 nm, the ordinate is about 10-100, so choose B