How does the width of the slits affect the intensity in diffraction?
Furthermore, how does the width of the slits affect the intensity?
In single slit diffraction calculations, the resultant amplitude is obtained by dividing the slit width into a large number of equal segments. So amplitude should be proportional to slit width. The intensity is proportional to the square of slit width, as intensity is proportional to the square of the amplitude.
Also Know, what is the relation between intensity and fringe width? It depends upon the wavelength or frequency of light. Intensity of the incident light has no relation with the fring width in any case. It's the measure of the power incident on a surface per unit area. The brightness of the fringes are affected by intensity of incident light not the fringe width.
Secondly, how does the width of the slits affect the interference pattern?
The separation of the interference fringes depends on the slit separation. If now the slit width is increased the width of the diffraction envelope is decreased whilst the separation of the interference fringes stays the same. So less interference fringes will be visible.
What happens when you increase the number of slits in a diffraction grating?
The grating intensity expression gives a peak intensity which is proportional to the square of the number of slits illuminated. Increasing the number of slits not only makes the diffraction maximum sharper, but also much more intense. Such a multiple-slit is called a diffraction grating.