How much of the Sun\'s light (by percent) comes through the polarizer? Is this s

Question

How much of the Sun's light (by percent) comes through the polarizer? Is this safe to look at with the naked eye? Refer to #7 above: A second, identical linear polarizer is held behind the first polarizer. How much of the original light from the Sun comes through the 2^nd polarizer if the angle between the 1^st and 2^nd polarizer is 0 degree? 30degree? 45degree? 90degree? Answers: 1/2 or 50 percentage 3/8 or 37.5 percentage 1/2 or 25 percentage 0 Refer to #8 above: Place a 3^nd identical linear polarizer between the other two polarizers when they are at 90d to each other. The 3^nd polarizer is placed so that its angle is 45d to each of the others. How much sunlight passes now passes through the polarizers? Answer: 1/8 or 12.5 percentage

Explanation / Answer

7a)
1st polarizer always polarizes light in 1 direction hence only 50 % of light passes through
Answer: 50 %
b)
It's not safe as light can still damage eye

8)
Let say original intenity was Io
Intensity after 1st polarizer = Io/2

for 2nd polariser:
I = Io/2 * cos^2 thetha
a)
I = Io/2 * cos^2 thetha
I = Io/2 * cos^2 0
    = Io/2
Which is 50 %

b)
I = Io/2 * cos^2 thetha
I = Io/2 * cos^2 30
    = Io/2 * 0.75
    = 0.375 Io
Which is 37.5 %

c)
I = Io/2 * cos^2 thetha
I = Io/2 * cos^2 45
    = Io/2 * 0.5
    = 0.25 Io
Which is 25 %

d)
I = Io/2 * cos^2 thetha
I = Io/2 * cos^2 90
    = Io/2 * 0
    = 0
Which is 0 %

9)
After 1st polariser intensity = Io/2

After 2nd polariser,
I = Io/2* cos ^2 45
   = Io/2* 1/2
    = Io/4

After 3rd polariser,
I = Io/4* cos ^2 45
   = Io/4* 1/2
    = Io/8
Answer: 1.8 or 12.5 %

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