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10 marksAn optical sensor alternates between a green source of wavelength 520 nm and a red source of wavelength 650 nm. Treat each source as monochromatic and use its wavelength in a vacuum. Each source emits 2.0 μJ of light energy in a burst.
Use c = 3.00 × 10⁸ m s⁻¹ and h = 6.63 × 10⁻³⁴ J s.
(a) Calculate the frequency of the green light. [2]
(b) Calculate the energy of one green photon and one red photon. [3]
(c) Calculate the number of photons emitted in one green burst. [2]
(d) A technician claims that equal-energy bursts contain equal numbers of photons. Calculate the ratio (red photon count)/(green photon count) and explain whether the claim is correct. [3]