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Assertion (A): For the radiation of a frequency greater than the threshold frequency, the photoelectric current is proportional to the intensity of the radiation. - Physics

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प्रश्न

  • Assertion (A): For the radiation of a frequency greater than the threshold frequency, the photoelectric current is proportional to the intensity of the radiation.
  • Reason (R): Greater the number of energy quanta available, the greater the number of electrons absorbing the energy quanta and the greater the number of electrons coming out of the metal.

विकल्प

  • If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

  • If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.

  • If Assertion is true but Reason is false.

  • If both Assertion and Reason are false.

MCQ

उत्तर

If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Explanation:

When the frequency of the incident radiation exceeds the threshold frequency, the photoelectric current is proportional to the intensity of the radiation. As a result, the assertion is correct. As the intensity rises, so does the number of energy quanta accessible. By absorbing more energy quanta, a bigger number of electrons are emitted. A higher number of electrons equals a higher current. As a result, the photoelectric current becomes proportional to radiation intensity. So, the reason is also true, and it adequately explains the assumption.

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Experimental Study of Photoelectric Effect
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2023-2024 (March) Board Sample Paper

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Monochromatic radiation of wavelength 640.2 nm (1 nm = 10−9 m) from a neon lamp irradiates photosensitive material made of caesium on tungsten. The stopping voltage is measured to be 0.54 V. The source is replaced by an iron source and its 427.2 nm line irradiates the same photo-cell. Predict the new stopping voltage.


Every metal has a definite work function. Why do all photoelectrons not come out with the same energy if incident radiation is monochromatic? Why is there an energy distribution of photoelectrons?


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