JEE Mains · Physics · STD 12 - 11. Dual nature of radiation and matter
The work function of a substance is \(3.0\ \mathrm{eV}\). The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately _______.
- A \(215 \mathrm{~nm}\)
- B \(414 \mathrm{~nm}\)
- C \(400 \mathrm{~nm}\)
- D \(200 \mathrm{~nm}\)
Answer & Solution
Correct Answer
(B) \(414 \mathrm{~nm}\)
Step-by-step Solution
Detailed explanation
For \(P.E.E.\) : \(\lambda \leq \frac{h c}{W_e}\) \(\lambda \leq \frac{1240 \mathrm{~nm}-\mathrm{eV}}{3 \mathrm{eV}}\) \(\lambda \leq 413.33 \mathrm{~nm}\) \(\lambda_{\max } \approx 414 \mathrm{~nm}\) for \(P.E.E.\)
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