λ = 5.7 X 10⁻⁷m
On using quantum dot, it is 351
Step-by-step explanation:
Given-
Frequency, f = 5.20 x 10^14 Hz
Speed of light, c = 3 X 10⁸ m/s
Wavelength, λ = ?
We know,
λ f = c
λ = c / f
λ =

λ = 5.7 X 10⁻⁷m
Dot = 2 X 10⁻⁴
So,
2 X 10⁻⁴ / 5.7 X 10⁻⁷m = 351