Waves from Two Slits Are in Phase at the Slits

question 15

Multiple Choice

Waves from two slits are in phase at the slits and travel to a distant screen to produce the third bright fringe of the interference pattern.The difference in the distance traveled by the waves is:

• A)half a wavelength
• B)a wavelength
• C)three halves of a wavelength
• D)two wavelengths
• E)three wavelengths