What is the exact speed of light in vacuum ?

Define refractive index of a tranparent medium . The speed of light in a medium of absolute refractive index 1.5 " is " 2xx10^(8)ms^(-1) . What is the speed of light in vacuum ?

What is the speed of light in air ?

When light moves from one medium to another (i) the frequency of light remains same and wavelength changes (ii) refractive index of a medium is the ratio of speed of light in vacuum and speed of light in medium (iii) refractive index of a medium is the ratio of wavelength of light in vacuum and wavelength in medium (iv) for denser medium, the value of refractive index is larger

State the laws of refraction of light. Explain the term 'absolute refractive index of a medium' and write an expression to relate it with the speed of light in vacuum.

For a given medium , the speed of light and the polarising angle are V and i_p respectively. Then from Brewster's law [C is the speed of light in vacuum ]