Phenomenon in which electric charges (electrons) are emitted from hot bodies is known as:
Correct answer: B. Thermionic emission
- A. Photoelectric emission
- B. Thermionic emission
- C. Oscillatory current
- D. None of the above
Explanation
The phenomenon in which electric charges (electrons) are emitted from hot bodies is known as "thermionic emission." In thermionic emission, electrons are emitted from the surface of a hot material. The process occurs when the thermal energy of the material is sufficient to overcome the work function (energy barrier) holding the electrons within the material.
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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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