A 60 W source emits monochromatic light of wavelength 662.5 nm. The number of photons emitted per second is
- A$$5\times10^{17}$$
- B$$2\times10^{20}$$
- C$$5\times10^{26}$$
- D$$2\times10^{29}$$
✓ Correct answer: B
Want the full step-by-step reasoning?