Let's solve the question: **Question:** "Consider a blackbody at 300K with maximum emissive power. Calculate the wavelength (μm) of the emissions." To solve this, we use **Wien's Displacement Law**: \[ \lambda_{max} = \frac{b}{T} \] where: - \( \lambda_{max} \) = peak wavelength (in meters) - \( b \) = Wien's constant (\(2.897 \times 10^{-3} \) m·K) - \( T \) = temperature (in Kelvin) Given \( T = 300\,K \): \[ \lambda_{max} = \frac{2.897 \times 10^{-3}}{300} \] \[ \lambda_{max} = 9.657 \times 10^{-6} \text{ m} \] Convert meters to micrometers (\( 1\,\mu m = 10^{-6} \) m): \[ \lambda_{max} = 9.657\,\mu m \] **Closest answer:** **9.7 μm** So, the correct option is **9.7 μm**.