Answer:
The correct option is a: 214 nm.
Explanation:
The wavelength (λ) of the light can be calculated as follows:
[tex] \lambda = \frac{yd}{nD} [/tex] (1)
Where:
y: is the distance of the 7th bright fringe on the screen from the central fringe = 10.0 cm
d: is the distance between the slits = 3.00x10⁻⁵ m
D: is the distance between the screen and the slits = 2.00 m
n = 7
By entering all the above values into equation (1) we have:
[tex] \lambda = \frac{yd}{nD} = \frac{0.10 m*3.00 \cdot 10^{-5} m}{7*2.00 m} = 214.3 nm [/tex]
Therefore, the correct option is a: 214 nm.
I hope it helps you!