What is the formula for calculating interference and diffraction?

The formula for calculating interference and diffraction depends on the specific situation and the type of interference or diffraction pattern being considered.

For double-slit interference, the formula for calculating the position of the bright fringes is given by:

y = mλL/d

where:
- y is the position of the bright fringe on the screen
- m is the order of the fringe (m = 0, ±1, ±2, ...)
- λ is the wavelength of the light
- L is the distance between the slits and the screen
- d is the distance between the two slits

For single-slit diffraction, the formula for calculating the position of the minima is given by:

sin(θ) = mλ/b

where:
- θ is the angle of diffraction
- m is the order of the minima (m = ±1, ±2, ...)
- λ is the wavelength of the light
- b is the width of the slit

These are just a few examples of formulas used in interference and diffraction calculations. The specific formula to use will depend on the particular situation and the type of interference or diffraction pattern being analyzed.

Interference

Young's Double-Slit Interference:

λ/d = sinθ

- λ: wavelength of light
- d: distance between the slits
- θ: angle of the bright or dark fringe from the central fringe

Multiple-Slit Interference:

λL/d = nλ

- L: distance between the slits and the screen
- n: order of the bright or dark fringe

Diffraction

Single-Slit Diffraction:

D = 2λL/w

- D: width of the central bright band
- L: distance between the slit and the screen
- w: width of the slit

Circular Aperture Diffraction:

D = 1.22λL/a

- D: diameter of the central bright spot
- L: distance between the aperture and the screen
- a: diameter of the aperture