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कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान 2nd PUC Class 12

A proton, a neutron, an electron and an α-particle have same energy. Then their de Broglie wavelengths compare as ______.

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प्रश्न

A proton, a neutron, an electron and an α-particle have same energy. Then their de Broglie wavelengths compare as ______.

पर्याय

  • λp = λn > λe > λα

  • λα < λp = λn > λe

  • λe < λp = λn > λα

  • λe = λp = λn = λα

MCQ
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उत्तर

A proton, a neutron, an electron and an α-particle have same energy. Then their de Broglie wavelengths compare as `underline(λ_α < λ_p = λ_n > λ_e)`.

Explanation:

According to de-Broglie a moving material particle sometimes acts as a wave and sometimes as a particle.

deiBroglie wavelength: According to de-Broglie theory, the wavelength of de-Broglie wave is given by

`λ = h/p = h/(mv) = h/sqrt(2mE) ⇒ λ  oo  1/p  oo  1/v  oo  1/sqrt(E)`

Where h = Plank's constant, m = Mass of the particle, v = Speed of the particle, E = Energy of the particle.

The smallest wavelength whose measurement is possible is that of γ-rays.

The wavelength of matter waves associated with the microscopic particles like electron, proton neutron, α-particle etc is of the order of 10–10 m.

We conclude from above that the relation between de-Broglie wavelength λ and kinetic energy K of the particle is given by

`λ = h/sqrt(2mK)`

Here, for the given value of energy K, `h/sqrt(2K)` is a constant.

Thus, `λ  oo 1/sqrt(m)`

∴ `λ_p : λ_n : λ_e : λ_α = 1/sqrt(m_p) : 1/sqrt(m_n) : 1/sqrt(m_e) : 1/sqrt(m_α)`

Comparing the wavelength of proton and neutron, mp = mn, hence λp = λn

As mα > mp therefore λα < λp

As me > mn therefore λe < λn

Hence. λα < λ= λn < λe

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पाठ 11: Dual Nature Of Radiation And Matter - Exercises [पृष्ठ ६९]

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एनसीईआरटी एक्झांप्लर Physics Exemplar [English] Class 12
पाठ 11 Dual Nature Of Radiation And Matter
Exercises | Q 11.05 | पृष्ठ ६९

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