Geometrical Optics

Time taken by light to travel in two different materials \(A\) and \(B\) of refractive indices \(\mu_{A}\) and \(\mu_{B}\) of same thickness is \(t_{1}\) and \(t_{2}\) respectively. If \(t_{2}-t_{1}=5 \times 10^{-10}\) s and the ratio of \(\mu_{A}\) to \(\mu_{B}\) is \(1: 2\). Then, the thickness of material, in meter is: (Given \(v_{\mathrm{A}}\) and \(v_{\mathrm{B}}\) are velocities of light in \(A\) and \(B\) materials respectively.)