phys1cquiz3 - Chapter 27 Wiens Displacement Law: max(T) =...

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Chapter 27 Wien’s Displacement Law: λ max (T) = 0.2898 x 10^-2 (m x K) where λ max is the wavelength at which the curve peaks and T is the absolute temperature of the object emitting the radiation Classical theory says that predicts that intensity of blackbody radiation should be infinite but experimental data shows that is should approach zero ultraviolet catastrophe Resonators have discrete energies E n , given by E n = nhf where n is a positive integer called a quantum number, f is the frequency of vibration of the resonator, and h is Planck’s constant, h = 6.626 x 10 -34 (J x s) When V is equal to or more negative than - V s , the stopping potential, no electrons reach C and the current is zero. The stopping potential is independent of the radiation intensity. The maximum kinetic energy of the photoeletrons is related to the stopping potential through the relationship, KE max = e - V s The maximum kinetic energy for liberated photoelectrons is KE max = hf - φ Where φ is called the work function of the metal, the minimum energy with which an electron is bound in the metal, can be found in a table Diffraction of X-rays by crystals: the condition for constructive interference is 2dsin Θ = m λ , where m = 1, 2, 3…. The change in wavelength between a scattered xray and an incident ray is called the Compton shift: ∆λ = λ - λ 0 = h/m e c x (1-cos θ ) where m e is the mass of the electron and Θ is the angle between the directions of scattered and incident photons, The quantity h/m e c is called the Compton wavelength and has a value of 0.00243 nm. The Compton shift depends on the scattering angle and not the wavelength. Energy of a photon: E = hf = hc/ λ Momentum of a photon: p = E/c = hc/c λ = h/ λ So, the de Broglie wavelength of a particle is λ = h/p = h / mv Further, frequency of waves is f = E/h The uncertainty principle: If a measurement of the position of
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This note was uploaded on 02/07/2009 for the course BIPN BIPN 140 taught by Professor Spitzer during the Fall '07 term at UCSD.

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phys1cquiz3 - Chapter 27 Wiens Displacement Law: max(T) =...

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