Visible light of wavelength 6000 × 10^-8 cm falls normally on a single slit and produces a diffraction pattern. It is found that the second…

Visible light of wavelength $\displaystyle 6000 \times 10^{-8} \mathrm{~cm}$ falls normally on a single slit and produces a diffraction pattern. It is found that the second diffraction minimum is at $\displaystyle 60$° from the central maximum. If the first minimum is produced at $\displaystyle \theta_1$, then $\displaystyle \theta_1$ is close to :