An instructor wishes to determine the wavelength of the light in a laser beam. to do so, he directs the beam toward a partition with two tiny slits separated by 0.170 mm. an interference pattern appears on a screen that lies 4.95 m from the slit pair. the instructor's measurements show that two adjacent bright interference fringes lie 1.60 cm apart on the screen.
what is the laser's wavelength (in nm) ?

laser wavelength = 549.5 nm

Explanation:

Given data

separation d =  0.170 mm = 0.170 × m

interference pattern distance D = 4.95 m

two adjacent bright interference width w = 1.60 cm = 1.60  × m

to find out

laser's wavelength

solution

we know that fringe width formula that is

width = wavelength × distance / separation

we put all these value here to find wavelength

wavelength = 1.60 × × 0.170 × / 4.95

wavelength = 549.5 nm

so laser wavelength = 549.5 nm