The potential difference and wavelength of light to stop the ejection of excited electrons from the photosensitive surface is shown in the given table.If the wavelength of light is changed to 10-5 m, then the potential difference required (X) to stop the electrons will be
Correct answer: A. X = 0 V.
- A. X = 0 V.
- B. X = 2 V.
- C. X > 2 V.
- D. 0 V < X < 2 V.
Explanation
The energy of light is inversely related to its wavelength, according to the equation E = hc/λ, where h is Planck's constant, c is the speed of light, and λ is the wavelength. A wavelength of 10-5 m corresponds to a low frequency and therefore low energy. If this energy is less than the work function of the material, no electrons will be excited, and a stopping potential (X) of 0 V is required since no electrons are ejected. Hence, the correct answer is X = 0 V. The other options assume that the energy is sufficient to eject electrons, which is not the case here.
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About Photons and the Particle Model of Light
The particle model treats light as photons with energy E equals hf and momentum related to wavelength. Questions involve the photoelectric effect, work function, threshold frequency, stopping potential and photon energy, while distinguishing particle behaviour from the wave description of interference and diffraction.
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