Concept: All objects with a temperature above absolute zero emit thermal radiation. The peak wavelength of this emission depends entirely on the object's absolute temperature.
Formula:$$ \lambda_{\text{max}} \times T = 2.898 \times 10^{-3} \text{ m\cdot K} \quad (\text{Wien's Displacement Law}) $$
Solution:- Warm-blooded animals have an average body temperature of about \( 310 \text{ K} \) (\( 37^\circ \text{C} \)).
- Using Wien's Law: \( \lambda_{\text{max}} = \frac{2.898 \times 10^{-3}}{310} \approx 9.3 \times 10^{-6} \text{ m} \).
- A wavelength of \( 9.3 \mu\text{m} \) falls squarely in the mid-infrared region of the electromagnetic spectrum.
Why other options are incorrect:Animals are not hot enough (like the Sun) to emit primarily in the visible (A) or ultraviolet (B) regions. X-rays (D) require extreme high-energy atomic transitions, completely unrelated to physiological thermal emission.
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