Candela is the luminous intensity, in the perpendicular direction of a surface _ square meter of a black body at the temperature of freezing platinum under a pressure of 101325 newtons per square meter.
Correct answer: B. 1/600000
- A. 1/300000
- B. 1/600000
- C. 1/900000
- D. 1/1200000
- E. 1/1500000
Explanation
The candela is the luminous intensity, in the perpendicular direction, of a surface of 1/600000 square meters of a blackbody at the temperature of freezing platinum under a pressure of 101325 newtons per square meter.
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About Dawn of Modern Physics
Classical physics cannot explain blackbody radiation and related observations, leading to Planck’s quantum theory, in which energy is emitted or absorbed in discrete packets. Photons provide the particle model of light, with energy and momentum linked to frequency and wavelength, including the photoelectric effect and its threshold frequency.
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