Radiation fundamentals (Wien’s displacement): The wavelength corresponding to the peak (maximum) emissive power of a blackbody varies inversely with absolute temperature (λ_max * T = constant). The blank in “wavelength corresponding to __________” should be filled with:

Introduction / Context:
Wien’s displacement law links blackbody temperature to the spectral position of peak emission. It is often tested by asking what physical quantity defines the peak.

Given Data / Assumptions:

• Ideal blackbody emission.
• Absolute temperature T measured in kelvin.
• λ_max is the wavelength at which emissive power is highest.

Concept / Approach:
Wien’s displacement states λ_max * T = constant. Thus as T increases, λ_max decreases. The “peak” refers to the wavelength of maximum monochromatic emissive power, i.e., maximum energy in the spectral distribution.

Step-by-Step Solution:

Verification / Alternative check:
Plot of blackbody spectral curves at various temperatures shows peak shift toward shorter wavelengths as T increases, confirming the inverse relationship.

Why Other Options Are Wrong:
“Minimum energy/minimum emissive power/average” do not define the spectral peak; “net radiative exchange” is a system-level quantity, not a spectral peak descriptor.

Common Pitfalls:
Confusing Wien’s law (peak position) with Stefan–Boltzmann law (total emission proportional to T^4) or Planck’s law (full spectral distribution).

Final Answer:
maximum energy (peak emissive power)