CBSE 2024 · Region 5 · Set 1 · Q22 · 3 marks
(a)Write Einstein's photoelectric equation. How did Millikan prove the validity of this equation?(b)Explain the existence of threshold frequency of incident radiation for photoelectric emission from a given surface.
(a)
Write Einstein's photoelectric equation. How did Millikan prove the validity of this equation?
(b)
Explain the existence of threshold frequency of incident radiation for photoelectric emission from a given surface.
Marking-scheme solution
(a)
$\displaystyle h \nu=h \nu_{0}+K_{\max }=h \nu_{0}+e V_{0}$
By finding the value of Planck's constant using the $\displaystyle V_{0}$ versus $\displaystyle \nu$ straight line plot for sodium.
(b)
Since $\displaystyle K_{\max }$ must be non-negative, photoelectric emission is possible only when $\displaystyle h \nu>h \nu_{0}$, which implies the existence of $\displaystyle \nu_{0}$.
Dual Nature of Radiation and MatterEinstein’s Photoelectric Equation: Energy Quantum of RadiationUnderstandshort_answermedium
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CBSE Class 12 Physics past-paper question from the 2024board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.