Answer:
Explanation:
Given:
λ1 = 920 nm
= 9.2 × 10^-7 m
λ2 = 656 nm
= 6.56 × 10^-7 m
c = 3 × 10^8 m/s
Wavelength, λ = velocity, c/frequency, f
Frequency, f1 = 3 × 10^8/9.2 × 10^-7
= 3.26 × 10^14 Hz
Frequency of the infra red = = 3.26 × 10^14 Hz
Frequency, f2 = 3 × 10^8/6.56 × 10^-7
= 4.57 × 10^14 Hz
Frequency of the visible light = 4.57 × 10^14 Hz