For what wavelength of light will the first-order dark fringe (the first dark fringe next to a central maximum) be observed at this same point on the screen

“other instruments such as gravimeters and magnetometers are also used in the search for petroleum. extracting crude oil normally starts with drilling wells into an underground reservoir. when an oil well has been tapped, a geologist (known on the rig as the "mudlogger") will note its presence. “ this is what i found on google i hope it

Answerwavelength;