Experiment to calculate wavelength

• For Light

  Measure distance to the screen, D with a ruler

  Measure fringe separation x with a ruler

  Measure slit separation with a Travelling microscope, a

  Vary distance, D and measure the fringe separation x

  Plot graph x against D

  X = lander * distance / a = y =mc+c

  Gradient = Lander / a

  Lander = Gradient * a
• Reduce uncertainty:

  Increase D to a maximum which will reduce uncertainty

  measure the distance between multiple fringes and divide by that number
• Fringe separation, x increases as it is directly proportional to distance, D Wavelength and slit separation must be kept constant
• If speakers are swapped - The maxima would turn into minima and mina would turn into maxima
• For Sound:

  Measure distance D and distance between the speakers a with a ruler

  measure x distance between maxima and minima with a microphone connected to a oscilloscope and move it parallel to the speakers