Experiments show that the wavelength shift produced when X-rays scatter from free…
PHYSICS · Single correct · AP · Physics 2: Algebra-based · Modern Physics · Modern Physics
Problem
Experiments show that the wavelength shift produced when X-rays scatter from free electrons depends on the scattering angle but is completely independent of the intensity of the incident beam. Which of the following best explains why this observation contradicts the classical wave model of light?
(a) Classical waves of higher intensity would be expected to transfer proportionally more energy and thus produce a larger wavelength change.
(b) Classical waves require that the scattered frequency equal the incident frequency because a free electron is a non-dispersive medium.
(c) In classical physics the scattered wave carries no linear momentum, so its wavelength must remain unchanged regardless of angle or intensity.
(d) A stationary electron could shift the wavelength only if the beam’s intensity were high enough to drive the electron into relativistic motion, which classical theory predicts.