MHT CET · Physics · Dual Nature of Matter
Sodium and copper have work functions \(2.3 \mathrm{~ev}\) and \(4.5 \mathrm{~ev}\) respectively. The ratio of threshold wavelength of sodium to that of copper is nearest to
- A \(1: 4\)
- B \(4 : 1\)
- C \(1 : 2\)
- D \(2: 1\)
Answer & Solution
Correct Answer
(D) \(2: 1\)
Step-by-step Solution
Detailed explanation
\( \phi = \frac{hc}{\lambda_0} \implies \lambda_0 \propto \frac{1}{\phi} \) \( \frac{\lambda_{0, \text{sodium}}}{\lambda_{0, \text{copper}}} = \frac{\phi_{\text{copper}}}{\phi_{\text{sodium}}} \)
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