Explain the pattern of diffraction produced by two slits by drawing a figure.

(N/A) The figure shows the intensity distribution for a double-slit experiment. The overall envelope represents the single-slit diffraction pattern,while the finer fringes within this envelope represent the double-slit interference pattern.
In a double-slit experiment,the resultant intensity pattern on the screen is a superposition of the single-slit diffraction pattern (from each individual slit) and the double-slit interference pattern. The broader diffraction peak contains several narrower interference fringes.
The number of interference fringes that appear within the central diffraction peak is determined by the ratio $\frac{d}{a}$,where $d$ is the distance between the two slits and $a$ is the width of each individual slit.
As the slit width $a$ becomes very small,the diffraction envelope becomes very broad and flat.
It is important to note that while interference is a necessary phenomenon for observing a diffraction pattern,the diffraction phenomenon itself is not required to observe a standard interference pattern.