7. A double-slit experiment uses coherent light of wavelength 633 nm with a slit separation of 0.100 mm and a screen placed 2.0 m away. (a) What is the distance between first-order and second-order bright fringes?

The distance between first-order and second-order bright fringes is 12.66mm.

Explanation:

The physicist Thomas Young establishes through its double slit experiment a relationship between the interference (constructive or destructive) of a wave, the separation between the slits, the distance between the two slits to the screen and the wavelength.

 (1)

Where is the distance between two adjacent maxima, L is the distance of the screen from the slits, is the wavelength and d is the separation between the slits.  

The values for this particular case are:

Notice that is necessary to express L and in units of milimeters.

⇒

⇒

Finally, equation 1 can be used:

Hence, the distance between first-order and second-order bright fringes is 12.66mm.

ammonium chloride & tallow

real, smaller and upside-down.   so the answer should be b.