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isaac physics polarisation q

For each polariser, the angle given is the one for which light is transmitted and is given clockwise from the vertical.

Vertically polarised light of amplitude 100Vm−1 and intensity 14Wm−2 is incident on the following combinations of polarisers (P1, then P2, then P3). Complete the values indicated in the table, giving all answers to 2 significant figures. The Polariser angles P1, P2 and P3 are from the vertical.
P1=10, P2=165, P3=95

it asks to find amplitude, intensity and the angle to the vertical of the light after is has passed through all the filters.

tia :smile:
Original post by ruby.slinger
For each polariser, the angle given is the one for which light is transmitted and is given clockwise from the vertical.

Vertically polarised light of amplitude 100Vm−1 and intensity 14Wm−2 is incident on the following combinations of polarisers (P1, then P2, then P3). Complete the values indicated in the table, giving all answers to 2 significant figures. The Polariser angles P1, P2 and P3 are from the vertical.
P1=10, P2=165, P3=95

it asks to find amplitude, intensity and the angle to the vertical of the light after is has passed through all the filters.

tia :smile:

You would use Malus' Law to calculate the intensity or amplitude. The law is I= I(0) cos^2(angle) or A= A(0) cos^2(angle). Those with a zero after it is the original, so original intensity or original amplitude. You would use the equation multiple times. Then, once you have figured out one, you can use intensity is directly proportional to amplitude ^2.

As for the angle, I believe that the polarised light runs parallel to the angle of the filter to the vertical, so I believe it would be the last one which is 95 but I am not certain

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