In the visible region of the spectrum the rotation of the plane of polarization is given by $ heta = a + \frac{b}{\lambda^{2}}$. The optical rotation produced by a particular material is found to be $30{^\circ}\ per\ mm$ at$\ \lambda = 5000\mathring{\mathrm{A}}$ and $50{^\circ}per\ mm$ at $\lambda = 4000\mathring{\mathrm{A}}$. The value of constant $a$ will be

Question

In the visible region of the spectrum the rotation of the plane of polarization is given by $	heta = a + \frac{b}{\lambda^{2}}$. The optical rotation produced by a particular material is found to be $30{^\circ}\ per\ mm$ at$\ \lambda = 5000\mathring{\mathrm{A}}$ and $50{^\circ}per\ mm$ at $\lambda = 4000\mathring{\mathrm{A}}$. The value of constant $a$ will be

Dr. Abubacker · Accepted Answer

(b) $	heta = a + \frac{b}{\lambda^{2}}$
$30 = a + \frac{b}{(5000)^{2}}$ and $50 = a + \frac{b}{(4000)^{2}}$
Solving for $a$, we get $a = - \ \frac{50{^\circ}}{9}per\ mm$

Explanation

Reviewed by Dr. Abubacker

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