A student sets up an experiment to investigate double-slit interference. The student uses light of a single wavelength from a laser to illuminate a double slit so that a pattern of interference fringes is observed on the screen.
The student finds that the fringes are very close together. What could the student decrease in order to increase the separation of the fringes on the screen?
the distance 
from the laser to the double slit
the distance 
from the double slit to the screen
the separation 
of the slits
the wavelength of the light from the laser
