In Young's double slit experiment, the $6^{\text {th }}$ maximum with wavelength ${ }^{\prime} \lambda_{1}{…
In Young's double slit experiment, the $6^{\text {th }}$ maximum with wavelength ${ }^{\prime} \lambda_{1}{ }^{\prime}$ is at a distance ${ }^{\prime} \mathrm{d}_{1}{ }^{\prime}$ from the central maximum and the $4^{\text {th }}$ maximum with wavelength $\lambda_{2}$
is at distance $\mathrm{d}_{2}$. Then $\frac{\mathrm{d}_{1}}{\mathrm{~d}_{2}}$ is