A body cools from 62,^oC to 50,^oC in 10, minutes and to 42,^oC in next 10, minutes . temperature of

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10-2.Transmission of Heat

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A body cools from $62\,^oC$ to $50\,^oC$ in $10\, minutes$ and to $42\,^oC$ in next $10\, minutes$. The temperature of the surrounding is ........... $^oC$

A

$16$

B

$26$

C

$36$

D

$21$

Solution

$\frac{62-50}{10}=\frac{1}{\mathrm{K}}\left(\frac{62+50}{2}-\theta\right)$

$\frac{50-40}{10}=\frac{1}{\mathrm{K}}\left(\frac{50+42}{2}-\theta\right)$

$\frac{12}{8}=\frac{56-\theta}{46-\theta} \quad\left(\theta \Rightarrow 26^{\circ} \mathrm{C}\right)$

Standard 11

Physics

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