What is a diffraction grating? what is a diffraction grating? a device used to grate cheese and other materials a musical instrument used to direct sound a plaque with a tiny circular aperture an opaque object with many closely spaced slits diffraction gratings are not covered in chapter 33.

An opaque object with many closely spaced slits

Explanation:

Diffraction grating is an opaque object which will have many close slits on it

Each slit will allow the light wave pass through it which incident on it.

So here each slit will behave like a secondary source which will transmit the light and the superposition of light is then observed on the screen

These large number of slits on the object is combined known as diffraction grating.

By the superposition of waves due to grating we will have pattern of maximum and minimum intensity on the screen and this intensity if highest at the mid point of screen and then decreases as we move away