de broglie | ncert class 12 | chapter 11| dual nature of radiation and matter |  numericals solutions

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NCERTCLASS12_CHAPTER11_SOLUTIONSPDF

11.12 Calculate the
(a) momentum, and
(b) de Broglie wavelength of the electrons accelerated through a potential difference of 56 V.

11.13 What is the
(a) momentum,
(b) speed, and
(c) de Broglie wavelength of an electron with kinetic energy of 120 eV.

11.14 The wavelength of light from the spectral emission line of sodium is 589 nm. Find the kinetic energy at which
(a) an electron, and
(b) a neutron, would have the same de Broglie wavelength.

11.15 What is the de Broglie wavelength of
(a) a bullet of mass 0.040 kg travelling at the speed of 1.0 km/s,
(b) a ball of mass 0.060 kg moving at a speed of 1.0 m/s, and
(c) a dust particle of mass 1.0 × 10–9 kg drifting with a speed of 2.2 m/s?

11.16 An electron and a photon each have a wavelength of 1.00 nm. Find
(a) their momenta,
(b) the energy of the photon, and
(c) the kinetic energy of electron.

11.17 (a) For what kinetic energy of a neutron will the associated de Broglie wavelength be 1.40 × 10–10m?
(b) Also find the de Broglie wavelength of a neutron, in thermal equilibrium with matter, having an average kinetic energy of
(3/2) k T at 300 K.

11.18 Show that the wavelength of electromagnetic radiation is equal to
the de Broglie wavelength of its quantum (photon).

11.19 What is the de Broglie wavelength of a nitrogen molecule in air at 300 K? Assume that the molecule is moving with the root-meansquare speed of molecules at this temperature. (Atomic mass of nitrogen = 14.0076 u)

 

 

de broglie numerical solutions _ Maharashtra Board Class 12 Chapter 15

Maharashtraboardsolutions

13. Calculate the wavelength associated with

an electron, its momentum and speed 

(a) when it is accelerated through a potential of 54 V,

 (b) when it is moving with kinetic energy of 150 eV.

 14. The de Broglie wavelengths associated E with an electron and a proton are same. What will be the ratio of

(i) their momenta 

(ii) their kinetic energies?

15. Two particles have the same de Broglie wavelength and one is moving four times as fast as the other. If the slower particle is an a-particle, what are the possibilities for the other particle?

[Ans: proton or neutron] 

16. What is the speed of a proton having de Broglie wavelength of 0.08 Å? [Anss 49.57 x 103 m s'] 

17. In nuclear reactors, neutrons travel with energies of 5 x 10^-21 J. Find their speed and wavelength.

Ans: 2.45 x 103 m s', 1.62 Å] 

18. Find the ratio of the de Broglie wavelengths of an electron and a proton when both are moving with the (a) same speed, (b) same energy and (c) same momentum? State which of the two will have the longer wavelength in each case? 

[Ans: (a) 1836, (b) electron; 42.85, electron; (c) 1, equal] F

 

 

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