Explanation:
Given that,
Wavelength of light, [tex]\lambda=600\ nm=6\times 10^{-7}\ m[/tex]
Angle, [tex]\theta=25^{\circ}[/tex]
We need to find the slit spacing for diffraction. For a diffraction, the first order principal maximum is given by :
[tex]d\sin\theta=n\lambda[/tex]
n is 1 here
d is slit spacing
[tex]d=\dfrac{\lambda}{\sin\theta}\\\\d=\dfrac{6\times 10^{-7}}{\sin(25)}\\\\d=1.41\times 10^{-6}\ m\\\\d=1.41\ \mu m[/tex]
So, the slit spacing is [tex]1.41\ \mu m[/tex].