AP EAMCET · PHYSICS · Thermal Properties of Matter
The emissivity of a perfect black body is increased to 16 times by increasing its temperature. If the initial temperature is \(\mathrm{T}\), then final temperature of that black body is
- A \(4 \mathrm{~T}\)
- B \(8 \mathrm{~T}\)
- C \(2 \mathrm{~T}\)
- D \(16 \mathrm{~T}\)
Answer & Solution
Correct Answer
(C) \(2 \mathrm{~T}\)
Step-by-step Solution
Detailed explanation
According to Stefan's law, \(\begin{aligned} & \mathrm{E}=\sigma \mathrm{T}^4 \\ & \frac{\mathrm{E}}{16 \mathrm{E}}=\frac{\sigma \mathrm{T}^4}{\sigma \mathrm{T}_2^4} \\ & \Rightarrow \mathrm{T}_2{ }^4=16 \mathrm{~T}^4 ; \mathrm{T}_2=2 \mathrm{~T} \end{aligned}\)
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