Question

a) A beam of monochromatic light is incident on a single slit of width 0.600 mm. A diffraction pattern forms on a wall 1.40 m beyond the slit. The distance between the positions of zero intensity on both sides of the central maximum is 1.90 mm. Calculate the wavelength (in nm) of the light. Round your answer to the nearest nm.

b) The hydrogen spectrum includes a red line at 656 nm and a blue-violet line at 434 nm. If light from a hydrogen lamp is incident on a diffraction grating that has 4500 groove/cm, what is the distance between the 2^nd order maxima for the red and blue-violet lines on the same side of the central maximum that is imaged on a large screen that is 1.50 m away?

Answer 1

Solution :

= da 0.6 mm 1 (2) het, the wavelength of the light ben. slit width 0:6*106 mm For n=fst orober minina (dark bringe or hero intensity), the position from central maxima is y=f.9 mm = 0.0019 Distance of the wall from slit =D = 10h We know, DA and d = 0.0019 mx 0,6*10mm = 814 nm leny 6 m