Question

The distance between slits in a double-slit experiment is decreased by a factor of 2. If the distance between fringes is small compared to the distance from the slits to the screen, the distance between adjacent fringes near the center of the interference pattern _______.

Answer 1

Answer:

the distance between adjacent fringes is increased by a factor o 2

Explanation:

To find how the distance between fringes is modified you can use the following formula for the calculation of the distance between fringes:

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

D: distance to the screen

d: distance between slits

λ: wavelength of the light

if d is decreased by a factor of 2, that is d'=1/2d, you have:

$\Delta y'=\frac{\lambda D}{d'}=\frac{\lambda D}{(1/2)d}=2\Delta y$

hence, the distance between adjacent fringes is increased by a factor o 2