Question

In a Young's double-slit experiment, light of wavelength 500 nm illuminates two slits which are separated by 1 mm. The separation between adjacent bright fringes on a screen 5 m from the slits is:______a. 0.10 cm b. 0.25 cm c. 0.50 cm d. 1.0 cm e. none of the above

Answer 1

Answer:

b. 0.25cm

Explanation:

You can solve this question by using the formula for the position of the fringes:

$y=\frac{m\lambda D}{d}$

m: order of the fringes

lambda: wavelength 500nm

D: distance to the screen 5 m

d: separation of the slits 1mm=1*10^{-3}m

With the formula you can calculate the separation of two adjacent slits:

$\Delta y=\frac{(m+1)(\lambda D)}{d}-\frac{m\lambda D }{d}=\frac{\lambda D}{d}\\\\\Delta y=\frac{(500*10^{-9}nm)(5m)}{1*10^{-3}m}=2.5*10^{-3}m=0.25cm$

hence, the aswer is 0.25cm