Question

In Young's 2-slit interference experiment, the wavelength of laser light can be determined. The two slits are separated by 0.16 mm. The screen is 1.4 m from the slits. It is observed that the second bright band is located 11 mm from the center of the pattern. Given this information, what is the wavelength of the laser light?

a. 1258 nm
b. 419 nm
c. 500 nm
d. 629 nm

Answer 1

d. 629 nm

Step-by-step explanation:

slit separation d = .16 x 10⁻³ m

distance of screen D = 1.4 m

distance of second bright band = 11 x 10⁻³

distance of second bright band = 2 x band width

= 2 x λ D /d

Putting the values given ,

11 x 10⁻³ = 2 x λ x 1.4 / .16 x 10⁻³

λ = 1.76 x 10⁻⁶ / 2.8

= .6285 x 10⁻⁶

= 628.5 x 10⁻⁹

= 629 nm approx .