A light wave encounters a surface which separates two media of n₁=1.18 and n₂=1.22 during its propagation. If the wave vector of the wave forms an angle of 22 with the normal to the surface when it propagates in medium 1, determine the direction of propagation of the light wave in medium 2. [6 Marks]

A light wave propagates in a medium 1 with a relative dielectric permittivity of 4 and relative magnetic permeability 0.65. During its pathway, the light wave encounters a surface whose normal has an angle of 40 with the direction of the light wave. The surface separates the first medium from another medium 2 that has a refractive index n₂=1.3. Determine the direction of the propagation of the light wave in medium 2 (angle of the propagation direction with the surface normal). [4 Marks].

Calculate the velocity of electrons ejected from a surface of sodium metal (work function=2.28 eV) when it is irradiated with a light wave of 2x10¹⁵Hz. [4 Marks].

Describe the advantages of wavelength dispersive spectroscopy over energy dispersive spectroscopy in studying the distribution of chemical elements within the microstructure of materials containing multiple chemical elements. [3 Marks].

Consider the two 1D lattice systems of monoatomic and diatomic chains shown in fig. 1, and 2, respectively. Sketch the corresponding dispersion curves assuming that the atoms in both lattices can move only along the chain direction. [4 marks].