Question

A. At what angle should the axes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized light to 15.

B.At what angle should the axes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized light to 112.

Answer 1

here,

A)

let the initial intensity of light be I0

when the unpolarized light passes through the first polarizer ,I1 = I0 /2

let the angle between the axis of polarizers be theta

the intensity of light passes throught the seccond polarizer I2 = I1 * ( cos(theta))^2

0.15 * I0 = 0.5 * I0 * (cos(theta))^2

solving for theta

theta = 56.8 degree

the angle between axis of polarizers is 56.8 degree

B)

let the initial intensity of light be I0

when the unpolarized light passes through the first polarizer ,I1 = I0 /2

let the angle between the axis of polarizers be theta

the intensity of light passes throught the seccond polarizer I2 = I1 * ( cos(theta))^2

0.112 * I0 = 0.5 * I0 * (cos(theta))^2

solving for theta

theta = 61.8 degree

the angle between axis of polarizers is 61.8 degree