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JEE Mains · Physics · STD 12 - 11. Dual nature of radiation and matter
The surface of a metal is illuminated altemately with photons of energies \(E _{1}=4\, eV\) and \(E _{2}=2.5\, eV\) respectively. The ratio of maximum speeds of the photoelectrons emitted in the two cases is \(2 .\) The work function of the metal in \(( eV )\) is\(......ev\)
- A \(2\)
- B \(4\)
- C \(8\)
- D \(10\)
Answer & Solution
Correct Answer
(A) \(2\)
Step-by-step Solution
Detailed explanation
\(E _{1}=\phi+ K _{1} \ldots(1)\) \(E _{2}=\phi+ K _{2}\) \(...(2)\) \(E _{1}- E _{2}= K _{1}- K _{2}\) Now \(\frac{ V _{1}}{ V _{2}}=2\) \(\frac{ K _{1}}{ K _{2}}=4\) \(K _{1}=4 K _{2}\) Now from equation \((2)\) \(\Rightarrow 4-2.5=4 K _{2}- K _{2}\) \(1.5=3 K _{2}\)…
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