Question

A red laser from the physics lab is marked as producing 632.8-nm light. When light from this laser falls on two closely spaced slits, an interference pattern formed on a wall several meters away has bright red fringes spaced 4.50mm apart near the center of the pattern. When the laser is replaced by a small laser pointer, the fringes are 4.64mm apart.Part AWhat is the wavelength of light produced by the pointer?Express your answer to three significant figures and include the appropriate units nm

Answer 1

Step-by-step explanation:

fringe separation or fringe width is directly proportional to wavelength .

Δ₁ / Δ₂ = wave length of first laser / wavelength of second laser

Δ₁ is fringe separation in first case and Δ₂ is fringe separation in second case.

putting the given values

632.8 / wavelength of second laser = 4.5 / 4.64

wavelength of second laser = 632.8 x (4.64 / 4.5)

= 652.48 nm

652 nm