A beam of vertically polarized light encounters two polarizing filters, as shown in the above figure. (a) Rank the three cases, A, B, and C, in order of increasing transmitted intensity. Indicate ties where appropriate. (b) Calculate the transmitted intensity for each of the cases in the figure, assuming that the incident intensity is 40.0 W/m2. Verify that your numerical results agree with the rankings in part (a).

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anonymous · Answer

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anonymous · Answer

Do you know malus law?? 

we have two malus laws
one when an unpolarized light is incident on a polarizer.. 

$$I = Io/2$$
Obvious right?? when a light is polarized by a polaroid.. half the vibrations are cut off and half of them allowed to transmit.. thus the intensity becomes one half..

next.. when an already polarized light is incident on another polarizer such that the axis of the polarizer is making an angle theta with respect the plane of vibration of the incident light 

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in that case.. only the component of the vibration parallel to the axis passes through, hence the component that pass through is COS(theta).. however since intensity is proportional to amplitude squared we get
$$I = Io Cos^{2}( \theta)$$

so now using these laws can you solve?

anonymous · Answer

i've tried solving it but i keep getting the wrong answer

vincent-lyon.fr · Answer

You have to find the angles, then work out the intensities.