Describe the simplest experiments to observe a diffraction pattern.

(N/A) $1$. Razor Blade Experiment: Place two razor blades such that their sharp edges are parallel and very close to each other,forming a narrow slit. When you look at a distant light bulb filament through this narrow slit,you will observe bright and dark fringes around the filament due to the diffraction of light.
$2$. Finger Experiment: Bring your fingers very close to each other and look at a distant light source through the narrow gap between them. You will observe a series of diffraction fringes.
$3$. Khadi Cloth Experiment: Look at a distant light bulb through a piece of fine-textured Khadi cloth. The fibers of the cloth act as a diffraction grating,and you will see bright and dark fringes around the light source.
$4$. Pinhole Experiment: Place an opaque screen with a tiny pinhole in front of a monochromatic light source (like a sodium lamp). When the light passes through this pinhole and falls on a distant screen,you will observe a diffraction pattern consisting of bright and dark fringes.