A certain substance is placed in a longitudinal magnetic field of a solenoid located between two Polaroids. The length of the tube wity substance is equal to `l = 30 cm`. Find the verdet constant if at a field strength `H = 56.5 kA//m`, the angle of rotation of polarization plane is equal to `varphi_(1) =+ 5^(@) 10`' for one direction of the field and to `varphi_(2) =- 3^(@) 20`,' for the opposite direction.

Explanation

Part of the rotations is due to Faraday effect and part of it is ordinary optical rotation. The latter does not change sign when magnetic field is revered. Thus
`varphi_(1) = alpha l + Vl H`
`varphi_(2) = alpha l - Vl H`
Hence `2Vl H = (varphi_(1) - varphi_(2))`
or `V = ((varphi_(1) - varphi_(2))/(2))// l H`
Putting the values
`V = (510ang min)/(2 xx .3 xx 56.5) xx 10^(-3) per A = 0.015 ang min//A`