Monochromatic light of frequency 6.0×10¹⁴ Hz is produced by a laser. The power emitted is 2×10⁻³ W. The number of photons emitted, on the average, by the source per second is:

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Accepted Answer

(4) 5×10¹⁵. Energy of one photon: E=h
u=6.63×10⁻³⁴×6.0×10¹⁴. E=3.98×10⁻¹⁹ J. The laser delivers P=2×10⁻³ J each second, and P=NE. N=(2×10⁻³)/(3.98×10⁻¹⁹)=5×10¹⁵ photons per second.

Monochromatic light of frequency 6.0×10¹⁴ Hz is produced by a laser. The power emitted is 2×10⁻³ W. The number of photons emitted, on the average, by the source per second is:

Step-by-step solution

Why the other options are wrong