Calculating of the angle of the disk.

문제)

Plane-polarized light is incident on a single polarizing disk with the direction of E parallel to the direction of the transmission axis. Through what angle should the disk be rotated so that the intensity in the transmit ted beam is reduced by a factor of

(a) 3.00.

(b) 5.00.

(c) 10.0.

 

풀이)

 

(a)

I reduced into 1 / 3.00 × I_max,

I / I_max = 1 / 3.00 = cos^2 θ.

cos θ = √(1 / 3.00). 

θ = arccos √(1 / 3.00) = 54.7˚

 

(b)

I reduced into 1 / 5.00 × I_max,

I / I_max = 1 / 5.00 = cos^2 θ.

cos θ = √(1 / 5.00). 

θ = arccos √(1 / 5.00) = 63.4˚

 

(c)

I reduced into 1 / 10.0 × I_max,

I / I_max = 1 / 10.0 = cos^2 θ.

cos θ = √(1 / 10.0). 

θ = arccos √(1 / 10.0) = 71.6˚