InterviewSolution
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InterviewSolution
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Explain method of davisson and Germer experiment and its results. |
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Answer» SOLUTION :In davisson and Germer experiment,by moving the detector on circular scale at different position. Angle between incident beam and scattered beam is called angle of scattering `(theta)` For different accelerating voltage (V) and different scattering angle `(theta)` intensity of scattered electron beam is measured. The experiment was performed by VARYING accelerating voltage from 44 to 68 V.  It was noted that a strong peak appeared in intensity (I) of the scattered electron for accelerating voltage of 54 volt and scattering angle at `theta=50^(@)`.This suggest that no.of electron scattered in maximum. Let stationary electrons is accelerated by volt V.Its kinetic energy, K=EV `therefore (1)/(2)mv^(2)=eV` `therefore (1)/(2)(m^(2)v^(2))/(m)=eV` `therefore (p^(2))/(2m)=eV` [`therfore` mv=p momentum] `therefore =sqrt(2meV)` Wavelength of matter WAVE (electron) `lambda=(h)/(p)` `therefore lambda=(h)/(sqrt(2meV))` substituting value of h,m,e `therefore lambda =(1.227)/(sqrt(V))` nm Theoretical value of wavelength of electron is 0.165 nm and experimental value obtained is 0.167 nm which are almost same. Here V =54 volt . Thus in this experiment there is excellent agreement between the theoretical value and experimentally obtained value of de-Broglie wavelength. Recently by double slit experiment,wave nature of light was demonstrated. In 1994 ,interference frings were obtained with the beams of iodine molecules then electron. In electron microscope wave nature of electron is used. |
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