Answer :
Answer:
Bright spot
Explanation:
When we have interference between two identical and coherent beams, the conditions for constructive interference (bright spots) and destructive interference (dark spots) are:
- Costructive interference: the path-length differences between the two waves is an integer multiple of the wavelength of the waves:
[tex]|d_1 - d_2| = n \lambda[/tex]
where the term on the left is the path difference, and [tex]\lambda[/tex] is the wavelength
- Destructive interference: the path-length differences between the two waves is an odd multiple of half the wavelength of the waves:
[tex]|d_1 - d_2| = (n+\frac{1}{2}) \lambda[/tex]
In this problem, the path-length difference is 2 wavelengths: so, it is an integer multiple of the wavelength, therefore the point is a point of constructive inteference (bright spot).