Which of the following statements about thermal radiation is always true?
A)A hot object emits photons with a longer wavelength than a cool object.
B)A hot object emits photons with a higher average energy than a cool object.
C)A hot object emits more radio waves than a cool object.
D)A hot object emits more X-rays than a cool object.

Question

Quizplus · Accepted Answer

The energy of a photon of thermal radiation is directly proportional to its frequency or inversely proportional to its wavelength. Therefore, a hot object emits photons with a higher average energy than a cool object. This is known as Wien's Law. Choices A, C, and D are all incorrect as they are not always true.

Which of the Following Statements About Thermal Radiation Is Always