Which of the following statements about thermal radiation is always true?
A)All the light emitted by hot object has higher energy than the light emitted by a cooler object.
B)A hot object emits more radiation per unit surface area than a cool object.
C)A hot object produces more total infrared emission than a cooler object.
D)A cold object produces more total infrared and radio emission per unit surface area than a hot object.

Question

Quizplus · Accepted Answer

According to the Stefan-Boltzmann law, the amount of radiation emitted by an object is proportional to its temperature to the fourth power. Therefore, a hot object will emit more radiation per unit surface area than a cool object. Option A is incorrect as it is not necessary that all the light emitted by a hot object will have higher energy than the light emitted by a cooler object. Option C is incorrect as it is not necessary that the total infrared emission of a hot object will be more than a cooler object. Option D is incorrect as a cold object will produce less total infrared and radio emission per unit surface area compared to a hot object.

Which of the Following Statements About Thermal Radiation Is Always