Question

How is the difference in paths taken by two originally in-phase light waves related to whether they interfere constructively or destructively? How can this be affected by reflection? By refraction?

a. Constructive interference occurs when the path difference is an odd multiple of half-wavelength; reflection introduces a phase shift.
b. Destructive interference occurs when the path difference is an even multiple of half-wavelength; refraction introduces a phase shift.
c. Constructive interference occurs when the path difference is an even multiple of half-wavelength; reflection introduces a phase shift.
d. Destructive interference occurs when the path difference is an odd multiple of half-wavelength; refraction introduces a phase shift.

Answer 1

The type of interference of light waves depends on the path difference being an even or odd multiple of half-wavelengths, with reflection and refraction altering the phase and potentially the interference pattern.

Step-by-step explanation:

The difference in paths taken by two originally in-phase light waves is directly related to the type of interference that occurs. Constructive interference happens when the path difference is an even multiple of the wave's half-wavelength. In contrast, destructive interference occurs when the path difference is an odd multiple of the wave's half-wavelength. The phase of the waves can also be affected by reflection and refraction. Reflection can introduce a phase shift, typically of 180°, which can turn constructive interference into destructive, and vice versa. When light waves undergo refraction by entering a different medium, their wavelength changes within that medium, which can alter the phase relationship between waves and hence affect the interference pattern.