JEE Mains · Physics · STD 12 - 11. Dual nature of radiation and matter
For a certain metal, when monochromatic light of wavelength \(\lambda\) is incident, the stopping potential for photoelectrons is \(3V_0\). When the same metal is illuminated by light of wavelength \(2\lambda\), then the stopping potential becomes \(V_0\). The threshold wavelength for photoelectric emission for the given metal is \(\alpha\lambda\). The value of \(\alpha\) is _______.
- A \(1\)
- B \(4\)
- C \(2\)
- D \(3\)
Answer & Solution
Correct Answer
(B) \(4\)
Step-by-step Solution
Detailed explanation
Using Einstein's photoelectric equation: \(eV_s = \dfrac{hc}{\lambda} - \Phi\) For the first case: \(3eV_0 = \dfrac{hc}{\lambda} - \Phi\) For the second case: \(eV_0 = \dfrac{hc}{2\lambda} - \Phi\) Multiplying the second equation by \(3\) and equating with the first equation:…
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