In: Physics
a) Unpolarized light passes through two Polariods. What is the angle between the two Polaroids axes so that the transmitted light is 25% of the original?
b) UUnpolarized light passes through two Polariods. The first Polaroid’s axis is horizontal. What is the angle of the 2nd Polaroid’s axis so that the transmitted light is 10% of the original?
c) Unpolarized light passes through three Polariods. The first Polaroid’s axis is vertical. The 2nd Polaroid’s axis is at 30° to the vertical. The 3rd Polaroid’s axis is also vertical. What is the orientation and intensity of the transmitted light?
a)
Io = intensity of unpolarized light
I1 = intensity of light after passing the first polaroid
I2 = intensity of light after passing the second polaroid = 0.25 Io = Io/4
= angle between the two polaroids
intensity of light after passing the first polaroid is given as
I1 = Io /2 Eq-1
intensity of light after passing the first polaroid is given as
I2 = I1 Cos2
using Eq-1
Io/4 = (Io /2) Cos2
Cos2 = 1/2
= 45
b)
Io = intensity of unpolarized light
I1 = intensity of light after passing the first polaroid
I2 = intensity of light after passing the second polaroid = 0.1 Io
= angle between the two polaroids
intensity of light after passing the first polaroid is given as
I1 = Io /2 Eq-1
intensity of light after passing the first polaroid is given as
I2 = I1 Cos2
using Eq-1
(0.1) Io = (Io /2) Cos2
Cos2 = 0.2
= 63.4
c)
Io = intensity of unpolarized light
I1 = intensity of light after passing the first polaroid
I2 = intensity of light after passing the second polaroid
I3 = intensity of light after passing the third polaroid
1 = angle between the first and second polaroid = 30
2 = angle between the second and third polaroid = 30
intensity of light after passing the first polaroid is given as
I1 = Io /2 Eq-1
intensity of light after passing the second polaroid is given as
I2 = I1 Cos21
I2 = ( Io /2 ) Cos230
intensity of light after passing the third polaroid is given as
I3 = I2 Cos22
I2 = ( ( Io /2 ) Cos230) Cos230
I2 = (0.5) Io Cos430
I2 = (0.28125) Io
hence the intensity is 0.28125 times the original intensity and the orientation is vertical.