# A beam of unpolarised light of intensity I_0 is passed through a polaroidA and then through another polaroid B which is oriented so that its princip

26 views
in Physics
closed
A beam of unpolarised light of intensity I_0 is passed through a polaroidA and then through another polaroid B which is oriented so that its principal plane makes an angle of 45^circ relative to that of A. The intensity of the emergent light is
A. I_(0)
B. I_(0)//2
C. I_(0)//4
D. I_(0)//8

by (97.3k points)
selected

Here, polaroid A polarises light.
Intensity of polarised light from A = (I_(0))/(2)
According to law of Malus,
Intensity of light emerging from B,
I_(B) = ((I_(0))/(2)) (cos 45^(@))^(2) = (I_(0))/(2)((1)/(sqrt(2)))^(2) = (I_(0))/(4)