Question

The drawing shows four sheets of polarizing material, each with its transmission axis oriented differently. Light that is polarized in the vertical direction is incident from the left and has an average intensity of 20 W/m2. Determine the average intensity of the light that emerges on the right in the drawing (a) when sheet A alone is removed, (b) when sheet B alone is removed, (c) when sheet C alone is removed, and (d) when sheet D alone is removed.

Answer 1

Answer:

Explanation:

At the point when light is vertically polarized is incident on the polarizer whose axes are situated at angle points $\theta _1 , \theta _2 , \theta _3$ the intensity power in the wake of going through all the polarisers is given by the Malus law, applied threefold for every one of the three axes.

$I = I_o \ cos \theta _1 \ cos \theta _2 \ cos \theta _ 3$

The heading of the direction of the polarization is equivalent to the pivoted axes of the polarizer provided that light is an electromagnetic wave, its course of polarization is therefore controlled by the electric field part.

∴

a)

When sheet A is removed, the transmitted light goes through B, at 30°.

$I = I_o \ cos ^2 \theta _1 \ cos ^2 \theta _2 \ cos^2 \theta _3$

$I = 20 \ cos ^2 30 \ cos ^2 60 \ cos ^2 30$

$I = 2.81 \ W/m^2$

b)

When B is removed, No light passes since the axis of A and the axis of C are perpendicular to each other.

c)

When C is removed, the intensity is indeed zero since the axes are aligned and adjusted at 90° to one another.

$\mathbf{d) \ I - I_o cos^2 (0) cos^2 (30) \ cos^2 (60)}$

$\mathbf{d = 3.75 \ W/m^2}$