question_answer

A double slit is illuminated by light of wavelength 600 nm. The slits are 0.1 cm apart and the screen is placed 1 m away. Calculate the angular separation of 10th maximum in radians.

Answer:

The angular separation of nth maxima is given by                         \[{{\theta }_{n}}=n\lambda /d\] For 10th maxima, the angular separation,             \[{{\theta }_{10}}=\frac{10\lambda }{d}\]          Here,     \[\lambda =600\,nm=6\times {{10}^{-7}}m\]             \[d=0.1cm=1\times {{10}^{-3}}m\] \[\therefore \]      \[{{\theta }_{10}}=\frac{10\times 6\times {{10}^{-7}}}{1\times {{10}^{-3}}}=60\times {{10}^{-4}}\] rad \[\Rightarrow \]   \[{{\theta }_{10}}=0.006\] rad