JEE Mains · Physics · STD 12 - 11. Dual nature of radiation and matter
An electron is travelling with a velocity \(v\) in free space and when it enters a medium, its velocity is reduced by \(20\%\). The de Broglie wavelength of electron in the medium is \(\alpha\lambda_0\), where \(\lambda_0\) is its de Broglie wavelength in free space. The value of \(\alpha\) is _______.
- A \(1.20\)
- B \(1.0\)
- C \(1.25\)
- D \(0.75\)
Answer & Solution
Correct Answer
(C) \(1.25\)
Step-by-step Solution
Detailed explanation
The de Broglie wavelength of an electron in free space is given by \(\lambda_0 = \dfrac{h}{mv}\). When the electron enters the medium, its velocity is reduced by \(20\%\). The new velocity is \(v' = v - 0.20v = 0.80v\). The de Broglie wavelength in the medium is…
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