

InterviewSolution
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De-Broglie wavelength of electron isλeand wavelength of the photon isλp. What is the relation betweenλeand λpif both have the same energy?1. \(\lambda_p \propto \sqrt \lambda_e\)2. \(\lambda_p \propto \lambda_e\)3. \(\lambda_p \propto \lambda_e^2\)4. \(\lambda_p \propto {1 \over \lambda_e}\) |
Answer» Correct Answer - Option 3 : \(\lambda_p \propto \lambda_e^2\) CONCEPT:
λ = h/p whereλ is de Broglie wavelength,h is Plank's const, and p is the momentum.
\(λ=\frac{h}{\sqrt{2mE}}\) whereλ is de Broglie wavelength,h is Plank's const, m is the mass of an electron, and E is the energy of the electron. Theequation ofenergyof photons is given by: \(E=\frac{hc}{λ}\) where E isenergy, h is the Planck constant, c is the speed of light in a vacuum and λ is the photon's wavelength. EXPLANATION: Given that: \(\lambda_e ={ h\over\sqrt{( 2 mE}) }~and~\lambda_p = {hc \over E}\) \(\lambda_e^2 ={ h^2\over{( 2 mE}) }\) \(\lambda_e^2 ={ h^2\over{ 2 m({hc \over \lambda_p}}) }\) \(\lambda_e^2 ={ h^2\over{ 2 m({hc }}) } \lambda_p\) \(\lambda_e^2 \propto \lambda_p\) Sothe correct answer isoption 3. |
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