Coherent light from a sodium-vapor lamp is passed through a filter that blocks everything except for light of a single wavelength. It then falls on two slits separated by 0.420 . In the resulting interference pattern on a screen 2.14 mm away, adjacent bright fringes are separated by 2.90 . What is the wavelength of the light that falls on the slits?

The wavelength of the light that falls on the slit is 5.692 × 10⁻⁴m

Explanation:

Here we have

Fringe separation = 2.90 mm = 0.0029 m

Slit separation = 0.420 mm = 0.00042 m

Distance from slits to screen = 2.14 mm = 0.00214 mm

Wavelength is given by the following relation;

Therefore;

The wavelength of the light that falls on the slit = 5.692 × 10⁻⁴m.

the part of the wave he is travelling on is the crest

vapour or gas assuming atmospheriv pressure