Unpolarized light falls on the two polarizing sheets placed one on top of the other. What must be the angle between the characteristic directions of the sheets if the intensity of the transmitted light is the one-third intensity of the incident beam?

b) Waveplates formed from accurate thicknesses of birefringent material may be used to change the polarisation state of light. For each of the following configurations of incident light (travelling horizontally), linear polarisers and waveplates, describe the polarisation state of the transmitted light: (i) Unpolarised light incident on a linear polariser with transmission axis vertical, followed by a half-wave plate with o and e axes at ±45 degrees to the vertical. (ii) As (i) above, but the half-wave plate is replaced by a quarter-wave plate at the same orientation (iii) As (i) above, but the linear polariser is rotated with axis at 30 degrees from the vertical, then the half-wave plate. (iv) As (i) above, but the half-wave plate is rotated with o axis vertical and e axis horizontal.

A beam of light passes through three sheets of polarizing material as shown in the drawing. The orientation of transmission (polarizing) axis is labeled relative to the vertical. The incident beam of light is unpolarized and has an intensity of 650 W/m^2.a) Find intensity of beam transmitted after each polarizing material.b) Sketch direction of polarized light after each polarizing material.

FM radio wave at 150 MHz travels along the x-axis with a magnetic field polarized along the z axis, width Bmax = 10^-4 T. The wave is reflected οn metal surface which intersects vertically the course of the wave at position x = 0. After reflection, the electric field changes phase by 180o but its width as well as its magnetic field remains the same. a) Write the expressions for the electric and the magnetic field of the incident and reflected EM wave. b) Calculate the parameters λ, β, ω, Ε max, the intensity and density of energy per unit volume of the EM field, as well as the force exerted by the EM radiation on surface if it has an area of ​​500 m^2. (c = 3x10^8 m/s, μ0, ε0 known).