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Physics - Modern Physics Question with Solution | TestHub

PhysicsModern PhysicsMiscellaneousEasy2 minPYQ_2020

PhysicsEasysingle choice

An electron accelerated under a potential difference of $V$ volt has a certain wavelength $λ$ . It is known that the mass of a proton is about $1800$ times the mass of an electron. If a proton has to have the same wavelength $λ$ , then it will have to be accelerated under the potential difference of

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Answer:

Solution:

Wavelength $λ = \frac{h}{\sqrt{2 m q V}}$

$\Rightarrow m q V = \frac{h^{2}}{2 λ^{2}}$

$\Rightarrow m V = \frac{h^{2}}{2 λ^{2} q} = C o n s t a n t$

(since, $λ$ and q are same for electron and proton both)

$∴ V \propto \frac{1}{m}$

$\Rightarrow \frac{V_{P}}{V_{e}} = \frac{m_{e}}{m_{P}}$

$\Rightarrow V_{P} = (\frac{m_{e}}{m_{P}}) . V_{e} = \frac{V}{1800} v o l t$

Stream:NTA_ABHYAS_NEETSubject:PhysicsTopic:Modern PhysicsSubtopic:Miscellaneous

⏱ 2mℹ️ Source: PYQ_2020

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