In the Young's experiment with sodium light, the slits are 0.589 m apart. What is the angular width of the third maximum ? Given that λ = 589 nm.

$\sin^{-1}(3 × 10^{-6})$ $\sin^{-1}(3 × 10^{-8})$ $\sin^{-1}(0.33 × 10^{-6})$ $\sin^{-1}(0.33 × 10^{-8})$

$\sin^{-1}(3 × 10^{-6})$

$x_n=\frac{nλD}{2d}$ or $\frac{x_n}{D}=\frac{nλ}{2d}$ $∴\sin θ=\frac{nλ}{2d}=\frac{3×589×10^{-9}}{0.589}$ $θ=\sin^{-1}(3 × 10^{-6})$