JEE Mains · Physics · STD 12 - 11. Dual nature of radiation and matter
When UV light of wavelength \(300 \mathrm{~nm}\) is incident on the metal surface having work function \(2.13 \mathrm{eV}\), electron emission takes place. The stopping potential is _______. (Given hc \(=1240 \mathrm{eV} \mathrm{nm}\) )
- A \(4 \mathrm{~V}\)
- B \(4.1 \mathrm{~V}\)
- C \(2 \mathrm{~V}\)
- D \(1.5 \mathrm{~V}\)
Answer & Solution
Correct Answer
(C) \(2 \mathrm{~V}\)
Step-by-step Solution
Detailed explanation
\(\frac{\mathrm{hc}}{\lambda}-\phi=\mathrm{eV}\) \(\Rightarrow \frac{1240}{300} \mathrm{eV}-2.13 \mathrm{eV}=\mathrm{eVs}\) \(\Rightarrow 4.13 \mathrm{eV}-2.13 \mathrm{eV}=\mathrm{eVs}\) \(\Rightarrow \text { So, } \quad \mathrm{V}_5=2 \mathrm{volt}\)
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