Sample interview questions: Describe the behavior of blackbody radiation and its relation to thermodynamics.
Sample answer:
Blackbody Radiation
Blackbody radiation is the electromagnetic radiation emitted by an ideal radiator at a given temperature. It possesses the following properties:
- Emission: A blackbody absorbs all incident radiation and emits a continuous spectrum of radiation over a wide range of wavelengths.
- Intensity: The intensity of blackbody radiation increases exponentially with wavelength according to Planck’s law.
- Wavelength of Maximum Emission: The wavelength at which the blackbody emits the maximum intensity is inversely proportional to its temperature, known as Wien’s displacement law.
Relation to Thermodynamics
Blackbody radiation plays a crucial role in thermodynamics:
- Stefan-Boltzmann Law: The total energy radiated by a blackbody is proportional to the fourth power of its temperature.
- Entropy: Blackbody radiation contributes to the entropy of a system, which is a measure of its disorder or randomness.
- Thermodynamic Equilibrium: A blackbody in equilibrium with its surroundings exchanges radiation with no net change in entropy.