In a double-slit interference experiment, interference fringes are observed on a distant screen. The width of both slits is then doubled without changing the distance between their centers.

a. What happens to the spacing of the fringes?

b. What happens to the intensity of the bright fringes?

Answer:a) It remains the same.

b) It decreases

Explanation:◇y = (wavelength*Length) / distance

The wavelength of light is constant.

d = distance between the two slit. The value of d does not change so the fringes as well will not change.

b) As the space between the two slit becomes wider, the diffraction of light waves will become wider too.

When the width of the two slits are doubled, the diffraction of light forms larger angles and the intensive of the bright fringes decreases.