In a routine Young’s double slit experiment the paral- lel beam of light incident on the slit plane is a mixture of wavelength distributed between` lambda + Deltalambda" and" lambda – Deltalambda`. Because of this the interference fringes are poorly defined compared to the ideal case of monochromatic light. It is understood that the central maxima and the first order maxima will be well resolved if there is no overlapping in the first order minima and the first order maxima. Write the values of `Deltalambda` so that the first order maxima is well resolved from the central fringe.

Answer

`Deltalambdalt(lambda)/(3)`