複選題

Problem 18
Which of the following descriptions are true regarding blackbody radiation, the photoelectric effect, and theoretical models for the specific heat of solids?
(A) The energy density spectra of blackbody radiation are independent of the material composition and the shape of the object forming the blackbody. Moreover, a blackbody is not necessarily black in color.
(B) In the Rayleigh-Jeans formula, the average energy of electromagnetic (EM) standing waves inside a blackbody was calculated using the equipartition principle, which is incorrect. Additionally, the number of standing waves per frequency is also inaccurate.
(C) In the high-temperature limit, the specific heat of solids, as predicted by Einstein's and Debye's models, approaches the classical limit of 3R, where R is the universal gas constant. However, in the low-temperature limit, Einstein's model overestimates the specific heat.
(D) Based on Einstein's photon hypothesis, EM waves can be treated as particles whose energy is proportional to their frequency and particle number. Consequently, the energy of EM standing waves inside a blackbody is quantized, which explains the physical origin of Planck's blackbody radiation formula.
(E) In the photoelectric effect, the stopping voltage is independent of the intensity of the incident EM wave but depends on its frequency f. The photoelectric current increases with increasing EM wave intensity as long as hf exceeds a certain threshold, where h is Planck's constant.