A parallel beam of light of wavelength 6000 A is incident normally on a slit of width 0.2 mm. The diffraction  pattern  is obsessed or a screen which is placed at the focal plane of a convex lens of focal length 50 cm. If the lens is pl,aced dose to the slit, the distance between the minima om both sides of central maximum will be

The angular separation of minima on both side of central maximum of single slit is 2 θ where e is given byesin⁡θ=λ  or  sin⁡θ=λ/d sin⁡θ=6000×10−100.2×10−3=3×10−3 or θ≈3×10−3rad (∵sin⁡θ≈θ) when tho lens is placed close to the slit, then x=ftan⁡θ≈fθ wherc x is the distarce of ftst minlmum from the contral maximum.The distance between two minima on both sides of ceDtral maximum is 2x=2fθ=2×0⋅5×3×10−3=3×10−3m=3mm