A double slit is illuminated by light of wave length 6000 A0 . The slits are 0.1cm apart and the screen is placed 1 m away. Then the angular position of 20th maxima is

The given values are λ=6000 A0=6000×10−10 m d=0.1 cm=1×10−3 m  n=20 Angular position of 20th  maxima is θ=20λd (∵ θ=nλd)                                                        =20×6000×10−101×10−3                                                         =12×10−610−3                                                               =12×10−3  rad