In Young's double slit experiment, the light of wavelength ' \lambda ' is used. The intensity at a point on the screen is ' T ' where the path difference is \lambda \frac{-}{4}. If ' \mathrm{I}_0 ' denotes the maximum intensity then the ratio of ' \mathrm{I}_0 ' to ' I ' is \left(\cos 45^{\circ}=1 / \sqrt{2}\right)