Question

Light is diffracted through a single slit. How would the diffraction pattern on the screen change if the slit were made narrower? Explain.

Answer 1

For diffraction through a single slit

where,  = wavelength of the light and ,w = width of the slit .

so if the slit were made narrorer the light will be more diffraced .

so more diffraction is observed as the slit width is reduced.

Also, in a single slit diffraction experiment, if the width of the slit is made narrower, then the size of the central diffraction band increses and the intensity of the central diffraction band decreases. The angular width of the central maximum is given by:

2Dλ/w . where D is the slit to screen distance . clearly as w decreases the angular width increases which means will will get broad pattern with reduced intensity .

Thank You.