Light of a certain wavelength and intensity ejects photoelectrons from a metal plate. Then this beam is replaced by another beam of smaller wavelength and smaller intensity. As a result:
Correct answer: C. K.E of the photoelectrons decreases, but the strength of the photoelectric current increases
- A. No change occurs
- B. Emission of photoelectrons stops
- C. K.E of the photoelectrons decreases, but the strength of the photoelectric current increases
- D. K.E of the photoelectrons decreases, but the strength of the photoelectric current decreases
Explanation
Correct. Smaller wavelength light results in more energetic photoelectrons, but the intensity may decreaseIn summary, the correct option is **c. K.E of the photoelectrons decreases, but the strength of the photoelectric current increases** based on the principles of the photoelectric effect.
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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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