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QJEEM19Phfa66: JEE Main 2019 Physics - Class 12 JEEM19Phfa66 Solution: A 2 mW laser operates at wavelength of 500 nm. The number of…

A 2 mW laser operates at wavelength of 500 nm. The number of photons that will be emitted per second is : [Given Planck's constant h = 6.6 × 10–34 Js, speed of light c = 3.0 × 108 m/s]

Multiple Choice Options

  • A 5 × 1015
  • B 1.5 × 1016
  • C 1 × 1016
  • D 2 × 1016

Step-by-Step Verified Solution

2×10−3=hcλdndt

dndt=2×10−3λhc

=2×10−3×500×10−96.6×10−34×3×108

=10006.6×3×10=5×1015

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