An unpolarized light of intensity \( I_0 \) passes through polarizer and then through a certain optically active solution and finally it goes to analyser. If the angle between analyser and polariser is \( 0^\circ \) and intensity of light emerged from analyser is \( \frac{3}{8} I_0 \), the angle of rotation of the light by the solution with respect to analyser is ______ degrees.
