Question 133: Wave Optics

Question

A system of three polarizers P
1
, P
2
, P
3
is set up such that the pass axis of P
3
is crossed with respect to that of P
1
.
The pass axis of P
2
is inclined at 60
o
to the pass axis of P
3
. When a beam of unpolarized light of intensity I0 is
incident on P
1
, the intensity of light transmitted by the three polarizers is I. The ratio ($${{{I_0}} \over I}$$) equals (nearly) :

Accepted Answer

When unpolarized light of intensity I
0
passes through P
1
, then intensity
I
1
= $${{{I_0}} \over 2}$$
as we know, I = I
0
cos
2
$$	heta $$
Given that angle between P
2
& P
3
= 60
o
and
P
1
and P
3
are crossed that means angle between P
1
and P
3
is 90
o
so angle between P
1
and P
2
= 90ÃÂ° Ã¢ÂÂ 60ÃÂ° = 30ÃÂ°
I
2
= $${{{I_0}} \over 2}{\cos ^2}30^\circ $$ = $${{3{I_0}} \over 8}$$
I
3
= $${{3{I_0}} \over 8}{\cos ^2}60^\circ $$ = $${{3{I_0}} \over {32}}$$ = I
$$ 	herefore $$ $${{{I_0}} \over I}$$ = $${{{I_0}} \over {{{3{I_0}} \over {32}}}}$$ = $${{32} \over 3}$$ = 10.67

Answer

10.67

Answer

5.33

Answer

16.00

Answer

1.80

Wave Optics

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