What is the photoelectric effect? State the laws of photoelectric emission.

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Emission of photoelectrons is an instantaneous process or we can say that there is no time delay in the photoemission process.

Phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation.

Both a and b

None of these

answer is C.

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Detailed Solution

Concept: We know that photo-electrons emit above a particular frequency of the incident light, hence photo electrons must be the cause of the photoelectric effect. Additionally, there is a cutoff frequency or minimum frequency below which no photo-electrons are generated.
Electrons are released when radiation, including X-rays, UV, and even visible light, hits metals. The photoelectric effect is the name given to this electron emission event.
Laws of Photoelectric Emission: The basic laws of photoelectric emission are the experimental observations on the photoelectric effect that can be summed up as follows.
(I) The threshold frequency is the lowest frequency for a specific photosensitive material below which photoemission entirely ceases, no matter how high the intensity may be.
(ii) As long as the frequency is higher than the threshold frequency, the photoelectric current for a particular photosensitive material is directly related to the amount of the incident radiation.
(iii) There is no time lag between the absorption of radiation and the emission of photoelectrons, making it clear that the photoelectric emission is an instantaneous process.
(iv) While the highest kinetic energy of the emitted electrons is independent of the intensity of the incident radiation, it is directly related to that frequency.
Hence, option 3 is correct.

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