A beam of natural light of intensity `I_(0)` falls on a system of two crossed Nicol prisms between which a tube filled with certain solution is placed in a longitudinal magnetic field of strength `H`. The length of the tube is `l`, the coefficient of linear absorption of solution is `x`, and the verder constant is `V`. Find the intensity of light transmitted through that system.

Explanation

On passing through the first (polarizer) Nicol he intensity of light becomes `(1)/(2)I_(0)` because one of the components has been cut. On passing through the solution the palne of polarization of the light beam will rotate by
`varphi = Vl H`
and its inetsnity will also decrease by a factor `e^(-chi l)`. The palne of vibraton of the light wave will then make an angle `90^(@) - varphi` with the principle direction of the analyzer Nicol. Thus by Malus' law the intensity of light coming out of the seond Nicol will be
`(1)/(2)I_(0).e^(-chi l). cos^(2).(90^(@) - varphi)`
`= (1)/(2)I_(0)e^(-chi l) sin^(2) varphi`.