Answer to Question #103185 in Optics for proloy

Question

discuss the dependence of image forming ability of an optical device on the phenomenon of diffraction .a diffraction gratting has 2000 lines .two sources of monochromatic lights emanating wave length landa1 and landa2 are just resolve by the gratting in the first order spectrum .if the mean of landa1 and landa2 is 600nm calculate difference between wavelength.

Answer 1

As per the given question,

Number of lines(Resolving power ) =2000

Mean of the wavelength $\overline{\lambda}=600nm$

let the difference between the wavelengths ($\lambda_1-\lambda_2)=\triangle \lambda$ )

We know that resolving power( $R)=\dfrac{\overline{\lambda}}{\triangle \lambda}$

Now, substituting the value,

$2000=\dfrac{600nm}{{\triangle \lambda}}$

$\triangle \lambda=\dfrac{600nm}{2000}=0.3nm$